Toan Bo Bai Tap Co Huong Dan Chuong Estelipit Ltdh Nam 2014
Transcript of Toan Bo Bai Tap Co Huong Dan Chuong Estelipit Ltdh Nam 2014
CHUYN ESTE LIPIT
A. TM TT L THUYT V ESTE
I. CTTQ MT S ESTE:
+ Este ca ru n chc vi axit n chc (este n chc): RCOOR ; CxHyO2
+ Este ca axit n chc vi ru a chc, c cng thc dng (RCOO)nR
+ Este ca axit a chc vi ru n chc, c cng thc dng R(COOR)n
+ Este ca axit a chc vi ru a chc, c cng thc dng Rn(COO)n.mRm
+ Este no n chc : CnH2nO2 + Este khng no c 1 ni i, n chc mch h: CnH2n - 2O2 (n 3)
+ Este no 2 chc mch h: CnH2n - 2O4 (n 2)
II. Danh php Tn Este = Tn gc hirocacbon ca ru + Tn axit ( trong ui oic i thnh at)
III. ng phn
- ng phn Axit
- ng phn este
- ng tp chc
- ng phn mch vng
Lu : CnH2nO2 c th c cc ng phn sau:- ng phn cu to:
+ ng phn este no n chc
+ ng phn axit no n chc
+ ng phn ru khng no c mt ni i hai chc
+ ng phn ete khng no c mt ni i hai chc
+ ng phn mch vng (ru hoc ete)
+ ng phn cc hp cht tp chc:
Cha 1 chc ru 1 chc anehit
Cha 1 chc ru 1 chc xeton
Cha 1 chc ete 1 chc anehit
Cha 1 chc ete 1 chc xeton
Mt ru khng no v mt ete no
Mt ete khng no v mt ru no
- ng phn cis tran (ng phn ru khng no c mt ni i hai chc - ng phn ete khng no c mt ni i hai chc - Mt ru khng no v mt ete no - Mt ete khng no v mt ru no)
- S ng phn este no n chc =2n-2 (1< n < 5)
- Cng thc tnh s triglixerit to bi glixerol vi n axit carboxylic bo =n2(n+1)*1/2
IV. T/c vt l
- Cc este l cht lng hoc cht rn trong iu kin thng,
- Cc este hu nh khng tan trong nc.
- C nhit si thp hn hn so vi cc axit hoc cc ancol c cng khi lng mol phn t hoc c cng s nguyn t cacbon. do gia cc phn t este khng to c lin kt hiro vi nhau v lin kt hiro gia cc phn t este vi nc rt km.Th d:CH3CH2CH2COOH
(M = 88) =163,50C
Tan nhiu trong ncCH3[CH2]3CH2OH
(M = 88), = 1320C
Tan t trong ncCH3COOC2H5(M = 88), = 770C
Khng tan trong nc
- Cc este thng c mi c trng
Iso amyl axetat c mi chui chn
Etyl butirat v etyl propionat c mi da
Geranyl axetat c mi hoa hngV. T/c ha hc
a) Thy phn trong mi trng kim(P x phng ha)
R-COO-R + Na-OH R COONa + ROH
b) Thy phn trong mi trng axit:R-COO-R + H-OH R COOH + ROH
* Nu Phng php P chuyn dich theo chiu thun
c) Ch :
- Este + NaOH 1Mui + 1 anehit
Este ny khi P vi dd NaOH to ra ru c nhm -OH lin kt trn cacbon mang ni i bc 1, khng bn ng phn ha to ra anehit.
VD: R-COOCH=CH2 + NaOH R-COONa + CH2=CH-OH
- Este + NaOH 1 Mui + 1 xeton
Este ny khi P to ru c nhm -OH lin kt trn cacbon mang ni i bc 2 khng bn ng phn ha to xeton.
+ NaOH R-COONa + CH2=CHOH-CH3
- Este + NaOH 2 Mui + H2O
Este ny c gc ru l phenol hoc ng ng phenol..
+ 2NaOH RCOONa + C6H5ONa + H2O
- Este + AgNO3/ NH3 ( P trng gng
HCOOR + 2AgNO3 + 3NH3 + H2O ( ROCOONH4 + 2Ag + 2NH4NO3
- Este no n chc khi chy thu c
d) P chy
VI. iu ch
a) P ca ancol vi axit cacboxylicRCOOH + ROH RCOOR + H2O
b) P ca ancol vi anhirit axit hoc anhirit clorua
+ u im: P xy ra nhanh hn v mt chiu
(CH3CO)2O + C2H5OH ( CH3COOC2H5 + CH3COOH
CH3COCl + C2H5OH ( CH3COOC2H5 + HCl
c) /c cc este ca phenol t P ca phenol vi anhirit axit hoc anhirit clorua(v phenol khng T/d vi axit cacboxylic)
(CH3CO)2O + C6H5OH ( CH3COOC6H5 + CH3COOH
CH3COCl + C6H5OH ( CH3COOC6H5 + HCl
d) P cng vo hirocacbon khng no ca axit cacboxylic
+ An Ken
CH3COOH + CH=CH CH3COOCH2 CH3
+ Ankin
CH3COOH + CH(CH CH3COOCH=CH2B. MT S BI TPV d - L thuyt
Cu 1: C cc nhn nh sau : (1) Este l sn phm ca P gia axit v ancol
(2) Este l hp cht hu c trong phn t c nhm - COO -
(3) Este no, n chc, mch h c CTPT l CnH2nO2, vi n 2
(4) Hp cht CH3COOC2H5 thuc loi este
(5) Sn phm ca P gia axit v ancol l este
Cc nhn nh ng l: A. (1), (2), (3), (4), (5). B. (1), (3), (4), (5) .C. (1), (2), (3), (4).D. (2), (3), (4), (5).Cu 2: Pht biu no sau y l ng?
A. phn bit benzen, toluen v stiren ( iu kin thng) bng phng php ha hc, ch cn dng thuc th l nc brom.
B. Tt c cc este u tan tt trong nc, khng c, c dng lm cht to hng trong cng nghip thc phm, m phm.
C. Phn ng gia axit axetic vi ancol benzylic ( iu kin thch hp), to thnh benzyl axetat c mi thm ca chui chn.
D. Trong phn ng este ha gia CH3COOH vi CH3OH, H2O to nn t -OH trong nhm
-COOH ca axit v H trong nhm -OH ca ancol.Cu 3: Metyl propionat l tn gi ca hp cht: A. CH3COOC2H5 B. CH3COOC3H7C. C3H7COOCH3D. C2H5COOCH3 Cu 4: Mt este n chc no mch h c 48,65 % C trong phn t th s ng phn este l: A. 1
B. 2
C. 3
D. 4
Cu 5: C3H6O2 c 2 ng phn T/d c vi NaOH, khng T/d c vi Na. CTCT ca 2 ng phn
A. CH3COOCH3 v HCOOC2H5
B.CH3CH2COOH v HCOOC2H5 C. CH3CH2COOH v CH3COOCH3
D. CH3CH(OH)CHO v CH3COCH2OH
Cu 6: S hp cht n chc c cng CTPT C4H8O2, u T/d vi dd NaOH
A.3
B.4
C.5
D.6
Cu 7: Cc ng phn ng vi CTPT C8H8O2 (u l n xut ca benzen) T/d vi NaOH to ra mui v Ancol l:
A. 2
B. 3
C. 4
D. 7
Hng Dn
C6H5COOCH3
HCOOCH2C6H5Cu 8: Thu phn este c CTPT: C4H8O2 ( xt H+ ), thu c 2 sn phm hu c X, Y.T X c th iu ch trc tip ra Y. Vy cht X l:
A. ancol metylic B. Etyl axetat C. axit fomic D. ancol etylic
Cu 9: Este c CTPT l C4H6O2, khi thu phn trong mi trng axit thu c hn hp cc cht u c kh nng trng gng. CTCT thu gn ca este l
A. HCOO-C(CH3) = CH2
B. HCOO-CH=CH-CH3.
C. CH3COO-CH=CH2.
D. CH2 =CH-COO-CH3.
Cu 10: Mt este c CTPT l C4H6O2 khi thy phn trong mi trng axit thu c imetyl xeton. CTCT thu gn ca C4H6O2 l cng thc no
A. HCOO-CH=CH-CH3 B. CH3COO-CH=CH2
C. HCOO-C(CH3)=CH2 D.CH2=CH-COOCH3Cu 11: Thu phn cht hu c X trong dd NaOH (d), un nng, c sn phm gm 2 mui v ancol etylic. Cht X l A. CH3COOCH2CH2Cl.
B. CH3COOCH2CH3.
C. ClCH2COOC2H5.
D. CH3COOCH(Cl)CH3. Cu 12: Cht hu c X c CTPT l C4H6O2Cl2. Khi cho X P vi dd NaOH thu c CH2(OH)COONa, etylenglicol v NaCl. CTCT ca X l:
A. CH2ClCOOCHClCH3.
B. CH3COOCHClCH2Cl.
C. CHCl2COOCH2CH3.
D. CH2ClCOOCH2CH2Cl.Cu 13: Hp cht hu c X cha mt loai nhom chc, co CTPT la C6H10O4. Khi thuy phn X trong NaOH thu c mt mui va 2 ancol ng ng lin tip nhau. X co CTCT la:
A. HOOC (CH2)2 COOH
B. CH3OOC CH2 COO C2H5 C. HOOC (CH 2)3 COO CH3
D. C2H5OOC CH2 - CH2 COOH
Cu 14: Cho s P : A (C3H6O3) + KOH ( Mui + Etylen glicol.
CTCT ca A l :
A. HOCH2COOCH3.
B. CH3COOCH2OH.
C. CH3CH(OH) COOH.
D. HCOOCH2CH2OH.Cu 15: Cho s : C4H8O2 ( X ( Y( Z( C2H6. CTCT ca X l
A. CH3CH2CH2COONa. B. CH3CH2OH.
C. CH2=C(CH3)-CHO. D. CH3CH2CH2OH.Cu 16: Cho cht X T/d vi mt lng va dd NaOH, sau c cn dd thu c cht rn Y v cht hu c Z. Cho Z T/d vi dd AgNO3/NH3 thu c cht hu c T. Cho T T/d vi dd NaOH li thu c cht Y. Cht X c th l:
A.HCOOCH=CH2
B.CH3COOCH=CH2
C.HCOOCH3 D.CH3COOCH=CH-CH3
Cu 17: Cho chui bin i sau: C2H2 X Y Z CH3COOC2H5 .X, Y, Z ln lt l
A. C2H4, CH3COOH, C2H5OH
B. CH3CHO, C2H4, C2H5OH
C. CH3CHO, CH3COOH, C2H5OH D. CH3CHO, C2H5OH, CH3COOHHng Dn
Cu 18: Thy phn hon ton este X bng dd NaOH. Sau khi P kt thc th s mol NaOH dng gp i s mol X. C
(1) X l este ca axit n chc v ancol hai chc
(2) X l este ca ancol n chc v axit hai chc
(3) X l este ca ancol n chc v axit n chc
(4) X l este c CTCT thu gn l RCOOC6H5(5) X l este ca ancol hai chc v axit hai chc
Cc pht biu ng l:
A. (1) (2) (3)
B. (3) (4) (5)
C. (1) (2) (3) (5)
D.(1) (2) (4) (5)Cu 19. Cht X T/d vi NaOH cho dd X1. C cn X1 c cht rn X2 v hn hp X3. Chng ct X3 thu c X4. Cho X4 trng gng thu c X5. Cho X5 T/d vi NaOH li thu c X2.Vy CTCT ca X l
A. HCOO- C(CH3)=CH2 B. HCOO-CH=CH-CH3
C. CH2=CH-CH2-OCOH D. CH2=CH-OCOCH3Cu 20: Dy cht no sau y c sp xp theo chiu nhit si ca cc cht tng dn
A. CH3COOH, CH3COOC2H5, CH3CH2CH2OH B. CH3COOH, CH3CH2CH2OH CH3COOC2H5C. CH3CH2CH2OH , CH3COOH, CH3COOC2H5 D. CH3COOC2H5 ,CH3CH2CH2OH , CH3COOHCu 21: Sp xp cc cht sau theo trt t tng dn nhit si: CH3COOH; CH3COOCH3; HCOOCH3; C2H5COOH; C3H7OH. Trng hp no sau y ng
A. HCOOCH3 < CH3COOCH3 < C3H7OH < CH3COOH < C2H5COOH.B. CH3COOCH3 < HCOOCH3 < C3H7OH < CH3COOH < C2H5COOH.
C. C2H5COOH< CH3COOH < C3H7OH < CH3COOCH3 < HCOOCH3
D. HCOOCH3< CH3COOCH3 < C3H7OH < C2H5COOH< CH3COOH
Cu 22: Cho s phn ng:
Este X (C4HnO2) Y Z C2H3O2Na.
CTCT ca X tha mn s cho l
A. CH2=CHCOOCH3.
B. CH3COOCH2CH3.
C. HCOOCH2CH2CH3.
D. CH3COOCH=CH2.V D - Bi TpCC CH KHI LM NHANH BI TP
- Nu cho bit s mol O2 phn ng ta nn p dng LBTKL tm cc i lng khc. nu bi cho este n chc ta c: neste + nO2(p) = nCO2 + 1/2nH2O- Nm chc l thuyt, cc phng trnh, cc gc hirocacbon thng gp khng phi nhp nhiu.
- t chy este no lun cho nCO2 = nH2O v ngc li. - Nu cho hay t p n suy ra este n chc th trong phn ng vi NaOH th s mol cc cht lun bng nhau.
- X phng ho este n chc cho 2 mui v nc => este ca phenol.
- Khi cho hh cht hu c tc dng vi NaOH:
+ to s mol ancol b hn s mol NaOH => hh ban u gm este v axit. Khi : nancol = neste; nmui = nNaOH(p) = nhh+ to s mol ancol ln hn s mol NaOH => hh ban u gm este v ancolDng 1: P chy
Cu 1: Khi t chy hon ton este no, n chc th P. Tn gi ca este l A. Metyl fomiat. B. Etyl axetat. C. Metyl axetat. D. n- Propyl axetat.
Hng DnGoi CT CnH2nO2
Ta c
Cu 2: t chy hon ton 7,4 gam hn hp hai este ng phn, thu c 6,72 lt CO2 (ktc) v 5,4 gam H2O. CTPT ca hai este l
A. C3H6O2B. C2H4O2C. C4H6O2D. C4H8O2Hng Dn
CTG ng thi cng l CTPT ca hai este l C3H6O2.
Cu 3: t chy hon ton hn hp 2 este, cho sn phm chy qua bnh P2O5d khi lng bnh tng ln 6,21 gam, sau cho qua dd Ca(OH)2 d c 34,5 gam kt ta. Cc este trn thuc loi:
A. Este no B. Este khng no C. Este no , n chc , mch h D. Este a chc
Hng Dn:
nn hai este l no n chc mch h.
Cu 4: Hp cht X T/d c vi dd NaOH un nng v vi dd AgNO3/NH3.Th tch ca 3,7 gam hi cht X bng th tch ca 1,6 gam O2 (cng k v nhit v p sut). t chy hon ton 1 gam X th th tch CO2 thu c vt qu 0,7 lt ( ktc). CTCT ca X A. O=CH-CH2 CH2OH B. HOOC-CHO C. CH3COOCH3 D. HCOOC2H5Hng DnDo cng k v nhit v p sut
t chy hon ton 1 gam X th th tch CO2 thu c vt qu 0,7 lt ( ktc) DCu 5: t chy hon ton 11,6 gam este X thu c 13,44 lt CO2(ktc) v 10,8 gam H2O. Mt khc Cho 11,6 gam este T/d vi dd NaOH thu c 9,6 gam mui khan. CT ca X l:
A. C3H7COOC2H5 B. C2H5COOC2H5 C. C2H5COOC3H7 D. CH3COOC3H7Hng Dn
nn este l no n chc c CTTQ: CnH2nO2 CnH2nO2 nCO2
n= 6 C6H12O2
RCOOR + NaOH RCOONa + ROH
0,1 0,1 0,1
Ta c 0,1.(R+67)=9,6=> R=29: C2H5-
Vy CTCT ca este l C2H5COOC3H7Cu 6: Hn hp X gm hai este no, n chc, mch h. t chy hon ton X cn 3,976 lt O2 (ktc) c 6,38 gam CO2. Mt khc X T/d vi dd NaOH c mt mui v hai ancol l ng ng k tip. CTPT ca hai este trong X A. C2H4O2 v C5H10O2 B. C2H4O2 v C3H6O2
C. C3H4O2 v C4H6O2 D. C3H6O2 v C4H8O2Hng DnDo X l este no n chc v T/d vi dd NaOH, c mt mui v hai ancol l ng ng k tip Goi CTca hai este l
Ta c
Phn ng chy
Ta c
Cu 7: X l hn hp 2 este ca cng 1 ancol no, n chc v 2 axit no, n chc ng ng k tip. t chy han ton 0,1 mol X cn 6,16 lt O2(ktc). un nng 0,1 mol X vi 50 gam dd NaOH 20% n P han ton, ri c cn dd sau P c m gam cht rn. Gi tr ca m l:
A. 13,5 B. 7,5 C. 15 D. 37,5
Hng DnDo X l este ca cng 1 ancol no, n chc v 2 axit no, n chc ng ng k tip.
Goi CTca hai este l
HCOOCH3 V CH3COOCH3
Cu 8: t chy hon ton 6,8 gam mt este A no n chc cha vng benzen thu c CO2 v H2O. Hp th ton b sn phm ny vo bnh ng dd Ca(OH)2 ly d thy khi lng bnh tng 21,2 gam ng thi c 40 gam kt ta. Xc nh CTPT, CTCT c th c ca A
A. 2
B. 3
C. 4
D. 5
Hng DnTm CTG: d dng tm c CTPT C8H8O2
4 CTCT: phenyl axetat; 3 p: o, m, p -metyl phenyl fomat
Cu 9: Hn hp Z gm hai este X va Y tao bi cung mt ancol va hai axit cacboxylic k tip nhau trong day ng ng (MX < MY). t chay hoan toan m gam Z cn dung 6,16 lit O2 (ktc), thu c 5,6 lit CO2 (ktc) va 4,5 gam H2O. CT este X va gia tri cua m tng ng la
A. CH3COOCH3 va 6,7 B. HCOOC2H5 va 9,5
C. HCOOCH3 v 6,7 D. (HCOO)2C2H4 va 6,6
Hng Dn
X, Y l 2 este no n chc
p dng LBTKL : m = + 4,5 - = 6,7 (gam)
t cng thc ca X, Y :
n = 2 ; n = 3 X : C2H4O2 HCOOCH3 Y : C3H6O2 CH3COOCH3
Cu 10: t chy hon ton hn hp hai este X, Y, n chc, no, mch h cn 3,976 lt oxi(ktc) thu c 6,38 gam CO2. Cho lng este ny T/d va vi KOH thu c hn hp hai ancol k tip v 3,92 gam mui ca mt axit hu c. CTCT ca X, Y ln lt l
A. C2H5COOC2H5 v C2H5COOC3H7 B. C2H5COOCH3 v C2H5COOC2H5
C. CH3COOCH3 v CH3COOC2H5 D. HCOOC3H7 v HCOOC4H9
Hng Dnt CTTB ca 2 este X, Y l: CnH2n+1COO
V X, Y u l este n chc, no, mch h nn: = = 6,38/44 = 0,145 mol
meste + = 44. + 18. meste = 3,31 gam
Ta c : mO (trong este) = meste mC mH = 3,31 12.0,145 2.1.0,145 = 1,28 gam
nO = 1,28/16 = 0,08 mol neste = 0,04 mol
nmui = neste = 0,04 mol Mmui = 14n + 84 = 3,92/0,04 = 98 n = 1Mt khc: = 3,31/0,04 = 82,75 12.1 + 46 + 14 = 82,75 = 1,77
Vy: X l CH3COOCH3 v Y l CH3COOC2H5 ( p n C
Cu 11: Este X no, n chc, mch h, khng c P trng bc. t chy 0,1 mol X ri cho sn phm chy hp th hon ton vo dd nc vi trong c cha 0,22 mol Ca(OH)2 th vn thu c kt ta. Thu phn X bng dd NaOH thu c 2 cht hu c c s nguyn t cacbon trong phn t bng nhau. Phn trm khi lng ca oxi trong X l:
A. 43,24% B. 53,33% C. 37,21% D. 36,26% Hng Dn Cn nCO20,1 0,1n
CO2 + Ca(OH)2 CaCO3 + H2O (1)
0,22 0,22 0,22
CO2 + CaCO3 + H2O Ca(HCO3)2 (2)
0,22 0,22
Theo (1), (2): thu c kt ta th: nCO2 < 0,22+0,22 = 0,44
Hay: 0,1n < 0,44 n < 4,4
X + NaOH to 2 cht c C = nhau X c 2 hoc 4 C
X khng c P trng gng n = 4 C4H8O2
Cu 12: Hn hp X gm hai cht hu c no, n chc T/d va vi 100 mldd KOH 0,4M, thu c mt mui v 336 ml hi mt ancol (ktc). Nu t chy hon ton lng hn hp X trn, sau hp th ht sn phm chy vo bnh ng dd Ca(OH)2(d) th khi lng bnh tng 6,82 gam. CT ca hai hp cht hu c trong X l A. CH3COOH v CH3COOC2H5.
B. C2H5COOH v C2H5COOCH3. C. HCOOH v HCOOC2H5.
D. HCOOH v HCOOC3H7.
Hng Dn
Nhn vo p n cho thy hn hp X gm 1 axit v 1 este
Goi CT hn hp X l: CnH2n+1COOH x mol v CnH2n+1COOCmH2m+1 y mol
Tc dng KOH
P chy hp th ht sn phm chy vo bnh ng dd Ca(OH)2(d) th khi lng bnh tng 6,82 gam
Cu 13: t chy hon ton 1 mol axit cacboxylic n chc X cn 3,5 mol O2. Trn 7,4 gam X vi lng ancol no Y (bit t khi hi ca Y so vi O2 nh hn 2). un nng hn hp vi H2SO4 lm xc tc. P hon ton c 8,7 gam este Z(trong Z khng cn nhm chc khc). CTCT ca Z
A. C2H5COOCH2CH2OCOC2H5 B. C2H3COOCH2CH2OCOC2H3
C. CH3COOCH2CH2OCOCH3 D. HCOOCH2CH2OCOH
Bi gii:
Phn ng chy: CXHyO2 + (x + -1)O2 ( xCO2 + H2O (1)
Theo (1), ta c : x + -1= 3,5 ( x + = 4,5 ( ( X : C2H5COOH
Ancol no Y : CnH2n+2-m (OH)m (1 ( m ( n) ( este Z : (C2H5COO)mCnH2n+2-m
( Meste = 73m + 14n + 2 m = hay 14n + 2 = 15m (2)
Mt khc < 2 hay 14n + 2 + 16m < 64 ( 30m + 2 < 64 (v m ( n) ( m < 2,1
T (2) ( ( ancol Y : C2H4(OH)2
( Z : C2H5COOCH2CH2OCOC2H5 Cu 14: Hn hp X gm axit axetic, etyl axetat v metyl axetat. Cho m gam hn hp X T/d va vi 200 ml dd NaOH 1M. Mt khc, t chy hon ton m gam hn hp X cn V lt O2(ktc) sau cho ton b sn phm chy vo dd NaOH d thy khi lng dd tng 40,3 gam. Gi tr ca V l:
A. 17,36 ltB. 19,04 ltC. 19,60 ltD. 15,12 lt
Hng Dn
X c cng thc chung CnH2nO2 vi nX = 0,2 molm dd tng = mCO2 + mH2O = 0,2.n.44 + 0,2.n.18 = 40,3 n = 3,25
nO2 = (3n-2)/2 = (3.3,25-2)/2 V = 17,36
Cu 15: t chy hon ton 3,42 gam hn hp gm axit acrylic, vinyl axetat, metyl acrylat v axit oleic, ri hp th ton b sn phm chy vo dd Ca(OH)2 (d). Sau P thu c 18 gam kt ta v dd X. Khi lng X so vi khi lng dd Ca(OH)2 ban u thay i nh th no
A. Tng 2,70 gam. B. Gim 7,74 gam. C. Tng 7,92 gam. D. Gim 7,38 gam.Hng Dn
hn hp gm axit acrylic, vinyl axetat, metyl acrylat v axit oleic u c CT l:
. p dng LBT khi lng v nguyn t ta c:
Khi lng X so vi khi lng dd Ca(OH)2 ban u s gim l:
=> D ng.
Cu 16: t chy hon ton 10 ml hi mt este X cn va 45ml O2 thu c kh CO2 v hi nc c t l th tch l 4: 3. Ngng t sn phm chy th th tch gim i 30 ml . Bit cc th tch o cng iu kin. Cng thc X l:
A. C4H6O2 B. C4H6O4 C. C4H8O2 D. C8H6O4Hng Dn
Do cc th tch o cng iu kin nn th tch chnh l s mol
Gi CT este l CxHyOzCxHyOz + O2 xCO2 + H2O
10 10 10x 5y
Ta c 10 = 45 (1)
T l kh CO2 v hi nc: (2)
Ngng t sn phm chy th th tch gim i 30 ml : 10x + 5y 30 = 10xy = 6 (3)
T (1),(2),(3) Cu 17: Mt este A (khng cha chc no khc) mch h c to ra t 1 axit n chc v ru no. Ly 2,54 gam A t chy hon ton thu c 2,688 lt CO2 (ktc) v 1,26 gam H2O. 0,1 mol A P va vi 12 gam NaOH to ra mui v ru. t chy ton b lng ru ny c 6,72 lt CO2 (ktc). Xc nh CTPT, CTCT ca A
A. C3H5(OOCCH3)3.
B. C3H5(OOCC2H5)3. C. C2H4(OOCCH3)3.
D. C3H5(OOCCH = CH2)3.Hng Dn
nA:nNaOH = 1:3
(RCOO)3R + 3NaOH 3RCOONa + R(OH)3 0,1 0,1
S nguyn t cacbon ca ru
Khi t chy A => CTG: C6H7O3 . V este 3 chc => CTPT A: C12H14O6= 254
Ta c: 3(R1 + 44) + 41 = 254 R1= 27 CH2 CHVy A: (C2H3COO)3C3H5
Cu 18: em ha hi 6,7 gam hn hp X gm CH3COOH, CH3COOC2H5, CH3COOCH3 v HCOOC2H5 thu c 2,24 lt hi (ktc). t chy hon ton 6,7 gam X thu c khi lng nc
A. 4,5 gam.
B. 3,5 gam.
C. 5 gam.
D. 4 gam.
Hng dnGi cng thc chung ca X l CnH2nO2 ( MX = 14n + 32 = = 67 ( n = 2,5
S chy : CnH2nO2 ( nCO2 + nH2O
( n = 2,5.0,1 = 0,25 mol ( m = 0,25.18 = 4,5 gam
Dng 2: Xc nh CTPT da vo t khi hi
Cu 1: Este A iu ch t ancol metylic c t khi so vi oxi l 2,3125. CT ca A l:
A. C2H5COOC2H5. B. CH3COOCH3. C. CH3COOC2H5. D. C2H5COOCH3Hng Dn
Do Este A iu ch t ancol metylic
Cu 2: Este X khng no, mch h, c t khi hi so vi oxi bng 3,125 v tham gia P x phng ho to ra mt anehit v mt mui ca axit hu c. C bao nhiu CT ph hp vi X
A.2
B.3
C.4
D.5
Hng Dn
P x phng ho to ra mt anehit v mt mui ca axit hu c
Cu 3: X l mt este no n chc, c t khi hi so vi CH4 l 5,5. Nu em un 2,2 gam este X vi dd NaOH d, thu c 2,05 gam mui. CTCT ca X l:
A. HCOOCH2CH2CH3B. HCOOCH(CH3)2 C. C2H5COOCH3 D. CH3COOC2H5
Hng Dn
2,2 gam este X
+ NaOH
0,025 0,025 mol
Cu 4: Este n chc X c t khi hi so vi CH4 l 6,25.Cho 20 gam X T/d vi 300 ml dd KOH 1M (un nng). C cn dd sau P thu c 28 gam cht rn khan. CTCT ca X l
A.CH2=CH-CH2COOCH3
B.CH2=CH-COOCH2CH3
C.CH3COOCH=CH-CH3
D.CH3-CH2COOCH=CH2 Hng Dn
Cho 0,2 mol X T/d vi 0,3 mol KOH 28 gam cht rn khan gm mui v KOH d
+ KOH
0,2 0,2 0,2 mol
Cu 5: Mt este to bi axit n chac v Ancol n chc c t khi hi so vi CO2 bng 2. Khi un nng este ny vi NaOH to ra mui c khi lng ln hn este P. CTCT ca este l:
A. CH3COOCH3 B. HCOOC3H7 C. CH3COOC2H5 D. C2H5COOCH3.Hng Dn
+ NaOH
Ta c mui c khi lng ln hn este P
Cu 6: Este to bi axit n chc v Ancol n chc c t khi hi so vi CO2 bng 2. Khi un nng este ny vi dd NaOH to mui c khi lng bng 93,18% lng este P. CTCT ca este
A. CH3COOCH3 B. HCOOC3H7 C. CH3COOC2H5. D. C2H5COOCH3
Hng Dn
+ NaOH
Ta c mui c khi lng bng 93,18% lng este P
T (1) v (2)
Cu 7: Mt este ca ancol metylic T/d vi nc brom theo t l mol 1: 1 thu c sn phm trong brom chim 35,08% theo khi lng . Este l:
A. metyl propyonat B. metyl panmitat C. metyl oleat D. metyl acrylat
Hng Dn
Theo gi thit 1 mol este + 1 mol Br2 . Gi M l khi lng mol este ta c:
R l C17H33 . Vy este l: metyl oleat
Cu 8: X phng ha hon ton 20,4 gam cht hu c X n chc bng dd NaOH thu mui Y v Z .Cho Z T/d vi Na d thu c 2,24 lt H2 ( ktc) . Nung Y vi NaOH rn thu c mt kh R, dR/O2=0,5 , Z T/d vi CuO nung nng cho sn phm khng c P trng bc . Tn gi ca X l:
A. Etyl axetat B. Iso Propyl axetat C. Propyl propinoat D. Isopropyl fomat
Hng DnX l este n chc to bi acid c mui Y l R-COONa v ancol n chc Z , R- OH.
S mol R-OH= s mol H =2,24: 11,2= 0,2 mol nn s mol X= 0,2 mol .
Kh R c khi lng mol = 32.0,5= 16: CH4 nn mui Y l CH3COONa.
Khi lng mol ca X = 20,4: 0,2 = 102g/mol
Ta c: CH3COOR = 59 + R= 102.
=> R= 43 nn R l C3H7 v este X l CH3-COOC3H7.
Cu 9: Thc hin P x phng ho cht hu c X n chc vi dd NaOH thu c mt mui Y v ancol Z. t chy hon ton 2,07 gam Z cn 3,024 lt O2 (ktc) thu c lng CO2 nhiu hn khi lng nc l 1,53 gam. Nung Y vi vi ti xt thu c kh T c t khi so vi khng kh bng 1,03. CTCT ca X l:
A. C2H5COOCH3 B. CH3COOC2H5 C. C2H5COOC3H7D. C2H5COOC2H5Hng Dn- Theo bi: X n chc, tc dng vi NaOH sinh ra mui v ancol
( X l este n chc: RCOOR.
Mt khc: mZ + = + ( 44.+ 18.= 2,07 + (3,024/22,4).32 = 6,39 gam
V 44.- 18.= 1,53 gam ( = 0,09 mol ; = 0,135 mol
> ( Z l ancol no, n chc, mch h c cng thc: CnH2n+1OH (n 1)
T phn ng t chy Z ( ==( n = 2.
Y c dng: CxHyCOONa ( T: CxHy+1 ( MT = 12x + y + 1 = 1,03.29
( ( C2H5COOC2H5 ( p n DDng 3: P x phng ha
TH1: Thy Phn Este n chc
Cu 1: Cho este X c CTPT l C4H8O2 T/d vi NaOH un nng c mui Y c phn t khi ln hn phn t khi ca X. Tn gi ca X l:
A. Metylpropionat B. Etyl axetat C. Propyl fomat D. Iso Propyl fomat
Hng Dn
C4H8O2 (X) =88 < C2H5ONa (Y) => CTCT l C2H5-COOCH3 Metylpropionat
Cu 2: Thu phn hon ton 8,8 gam mt este n chc, mch h X vi 100 ml dd KOH 1M (va ) thu c 4,6 gam mt ancol Y. Tn gi ca X l:
A. Etyl FomatB. Etyl PropionatC. Etyl Axetat D.Propyl Axetat
Hng Dn
Nhn vo p n nhn thy este X l no n chc, mch h
Gi CTCT este l CnH2n + 1COOCmH2m + 1
nru = nKOH = 0,1 mol
neste=nKOH =0,1 mol
Cu 3: Cho 12,9 gam mt este n chc, mch h T/d ht vi 150ml dd KOH 1M. Sau P thu c mt mui v anehit. S CTCT ca este tho mn tnh cht trn l:
A. 1 B. 2 C. 3 D. 4
Hng Dn:
HCOOCH=CH-CH3 v CH3COOCH=CH2
Cu 4: Hn hp M gm axit cacboxylic X, ancol Y (u n chc, s mol X gp hai ln s mol Y) va este Z c tao ra t X va Y. Cho hn hp M T/d va u vi dd cha 0,2 mol NaOH, tao ra 16,4 gam mui va 8,05 gam ancol. Cng thc cua X va Y la
A. HCOOH va CH3OH
B. CH3COOH va CH3OH
C. HCOOH va C3H7OH
D. CH3COOH va C2H5OHHng Dn:
Gi s mol: RCOOH a
ROH a
RCOOR b
Theo gi thit: ( nRCOONa = a + b = 0,2 mol. MRCOONa = 82 ( R = 15. (CH3). X l CH3COOH
Loi p n: A v C. (a + b) < nROH = a + b < a + b ( 0,1 < nROH < 0,2
40,25 < Mancol < 80,5. Loi p n B.
Cu 5: t chy hon ton 1 este n chc mch h X ( phn t c s lin kt < 3) c th tch CO2 bng 6/7 th tch O2 P ( cc th tch kh o cng iu kin) Cho m gam X T/d vi 200 ml dd KOH 0,7M c dd Y . C cn dd Y c 12,88 gam cht rn khan. Gi tr m l:
A. 8,88 B. 6,66 C. 10,56 D. 7,20
Hng Dn:
CTPT ca este l : CnH2n-2kO2 vi k R= 43 nn R l C3H7 v este X l CH3-COOC3H7.
Cu 8: Cho 27,6 gam hp cht thm X c CT C7H6O3 T/d vi 800 ml dd NaOH 1M c dd Y. Trung ha Y cn 100 ml dd H2SO4 1M c dd Z. Khi lng cht rn thu c khi c cn dd Z l
A. 31,1 gam.B. 56,9 gam.C. 58,6 gam.D. 62,2 gam.Hng Dn
= 0,2; = 0,8; = 0,2 0,6 mol NaOH phn ng vi C7H6O3.
HCOO-C6H4 OH + 3NaOH HCOONa + C6H4(ONa)2 + 3H2O
0,2 0,6 0,2 0,2
Khi lng cht rn = 0,2.68 + 0,2.154 + 0,1.142 = 58,6 gamCu 9: Cho axit salixylic (axit o-hiroxibenzoic) P vi anhirit axetic c axit axetylsalixylic (o-CH3COO-C6H4-COOH). P hon ton vi 43,2 gam axit axetylsalixylic cn va V lt dd KOH 1M. Gi tr ca V l
A. 0,72. B. 0,48. C. 0,96. D. 0,24.
Hng Dn
o-CH3COO-C6H4-COOH + 3KOH = CH3COOK +o-KO-C6H4-COOK+ 2H2O (1)
theo (1)
TH2: Thy phn hn hp Este n chc
Cu 1: X phng ha hon ton 1,99 gam hn hp hai este bng dd NaOH thu c 2,05 gam mui ca mt axit v 0,94 gam hn hp hai ancol l ng ng k tip nhau. CTCT ca hai este l:
A. HCOOCH3 v HCOOC2H5. B. C2H5COOCH3 v C2H5COOC2H5.
C. CH3COOC2H5 v CH3COOC3H7. D. CH3COOCH3 v CH3COOC2H5Hng Dn
Goi CTTB ca 2 Este l RCOO
RCOO + NaOH RCOONa + OHp dng LBTKL: meste + mNaOH = mmui + mru
1,99 + mNaOH = 2,05 + 0,94
Cu 2: X phng ha han ton 14,55 gam hn hp 2 este n chc X,Y cn 150 ml dd NaOH 1,5M. C cn dd thu c hn hp 2 ancol ng ng k tip v mt mui duy nht. CT 2 este l:
A. HCOOCH3, HCOOC2H5.
B. CH3COOCH3, CH3COOC2H5 C. C2H5COOCH3, C2H5COOCH3
D. C3H7COOCH3, C2H5COOCH3
Hng Dn
Goi CTTB ca 2 Este l RCOO
RCOO + NaOH RCOONa + OH 0,225 0,225 mol
Ta c
Cu 3: X l hn hp hai este ca cng mt ancol, no n chc v hai axit no, n chc, ng ng k tip. t chy hon ton 0,1 mol X cn 6,16 lt O2(ktc). un nng 0,1 mol X vi 50 gam dd NaOH 20% P hon ton, ri c cn dd sau P thu c m gam cht rn. Gi tr ca m l
A. 15 gam.B. 7,5 gamC. 37,5 gamD. 13,5 gamHng Dn
Do hai este ca cng mt ancol, no n chc v hai axit no, n chc, ng ng k tipGi CTTB ca hai este l n=2,5
P chy
Ta c
Cu 4: Hn hp X gm hai cht hu c. Cho hn hp X P va vi dd KOH th cn ht 100 ml dd KOH 5M. Sau P thu c hn hp hai mui ca hai axit no n chc v c mt ru no n chc Y. Cho ton b Y T/d vi Na c 3,36 lt H2 (ktc). Hai hp cht hu c thuc loi cht g
A. 1 axit v 1 este B. 1 este v 1 ancol C. 2 este D. 1 axit v 1 ancol Hng Dn
Ta c:
Ancol no n chc Y: CnH2n+1OH
CnH2n+1OH + Na CnH2n+1ONa + H2
0,3 mol 0,15 mol
Thu phn hai cht hu c thu c hn hp hai mui v mt ancol Y vi nY < nKOHVy hai cht hu c l: este v axit
Cu 5: Hn hp M gm hai hp cht hu c mch thng X v Y ch cha T/d va ht 8 gam NaOH c ru n chc v hai mui ca hai axit hu c n chc k tip nhau trong dy ng ng. Ru thu c cho T/d vi Na d c 2,24 lt H2 (ktc). X, Y thuc lai hp cht g A.1 axit v 1 este B.1 este v 1 ancol C.2 este D. 1 axit v 1 ancol Hng Dn
Thu phn hai X, Y v thu c nAncol = nNaOH. Vy X, Y l hai este.
Cu 6: Cho hn hp X gm ancol metylic v hai axit cacboxylic (no, n chc, k tip nhau trong dy ng ng) T/d ht vi Na c 6,72 lt H2 (ktc). Nu un nng hn hp X (c H2SO4 c lm xc tc) th cc cht trong hn hp P va vi nhau to thnh 25 gam este (gi thit P este ho t hiu sut 100%). Hai axit trong hn hp X l A. C3H7COOH v C4H9COOH. B. CH3COOH v C2H5COOH.
C. C2 H5COOH v C3H7COOH. D. HCOOH v CH3COOH.
Hng Dn
Gi CT hn hp X l
Do un nng hn hp X th cc cht P va vi nhau
T/d ht vi Na
COOH + CH3OH COOCH3 0,3 0,3 mol
Cu 7: Mt hn hp X gm 2 este n chc thy phn hon ton trong mi trng NaOH d cho hn hp Y gm 2 ru ng ng lin tip v hn hp mui Z
- t chy hn hp Y th thu c CO2 v hi H2O theo t l th tch 7:10
- Cho hn hp Z T/d vi lng va axit sunfuric c 2,08 gam hn hp A gm 2 axit hu c no. Hai axit ny va Pvi 1,59 gam natricacbonat
Xc nh CT ca 2 este bit rng cc este u c s nguyn t cacbon < 6 v khng tham gia phn ng vi AgNO3/NH3.
A. C2H5COOC2H5, CH3COOC3H7.
B. CH3COOCH3, CH3COOC2H5 C. C2H5COOCH3, C2H5COOCH3
D. C3H7COOCH3, C2H5COOCH3
Hng Dn
C: RCOOR RCOONa RCOOH + Na2CO3
0,03 0,015
t Y: nH2O > nCO2 => CH2 +1OH T ti l => = 2,33
=> 2 ru l: C2H5OH v C3H7OH (1)
axit = 2,08/0,03 = 69,3 => = 24,3 (2)
Do C < 6 v kt hp (1),(2) => C2H5COOC2H5, CH3COOC3H7 (khng c P vi AgNO3/NH3).
TH3: Thy phn Este ng phn ca nhau
Cu 1: Hn hp X gm hai este n chc l ng phn ca nhau. ung nng m gam X vi 300 ml dd NaOH 1M, kt thc cc P thu c dd Y v (m 8,4) gam hn hp hi gm hai anehit no, n chc, ng ng k tip c t khi hi so vi H2 l 26,2. C cn dd Y thu c (m 1,1) gam cht rn. Cng thc ca hai este l
A.CH3COOCH=CHCH3 v CH3COOC(CH3)=CH2 B. HCOOC(CH3)=CH2 v HCOOCH=CHCH3C. C2H5COOCH=CH2 v CH3COOCH=CHCH3. D. HCOOCH=CHCH3 v CH3COOCH=CH2.Hng Dn
= 52,4 CH3-CHO, C2H5-CHO loi p n A, B,
p dng BTKL ta c:
m + 0,3.40 = m 8,4 + 1,1 m = 21,5,
Cu 2: Hn hp A gm ba cht hu c X, Y, Z n chc ng phn ca nhau, u T/d c vi NaOH. un nng 13,875 gam hn hp A vi dd NaOH va thu c 15,375 gam hn hp mui v hn hp ancol c t khi hi so vi H2 bng 20,67. 136,50C, 1 atm th tch hi ca 4,625 gam X bng 2,1 lt. Phn trm khi lng ca X, Y, Z (theo th t KLPT gc axit tng dn) ln lt l:
A. 40%; 40%; 20% B. 40%; 20%; 40%
C. 25%; 50%; 25% D. 20%; 40%; 40%
Hng Dn
Ta c : ( MX =
Mt khc: X, Y, Z n chc, tc dng c vi NaOH ( X, Y, Z l axit hoc este
( CTPT dng: CxHyO2, d dng (
A ( ( ( p n B
Cu 3: t chy hon ton m gam hn hp X gm hai este ng phn cn dng 27,44 lt kh O2, c 23,52 lt CO2 v 18,9 gam H2O. Cho m gam X T/d ht vi 400 ml dd NaOH 1M, c cn dd sau P c 27,9 gam cht rn khan, trong c a mol mui Y v b mol mui Z (My < Mz). Cc th tch kh u o ktc. T l a : b l
A. 2 : 3 B. 4 : 3 C. 3 : 2 D. 3 : 5
Hng DnD dng c n CO2 = n H2O = 1,05 mol => Este no, n chc c cng thc chung CnH2nO2C nhhX = (3.1,05 2.1,225) : 2 = 0,35 mol (bo ton oxi) => n = 1,05 : 0,35 = 3
Hai este l HCOOC2H5 a mol; CH3COOCH3 b mol.
C a + b = 0,35 v 68a + 82b + 0,05.40 = 27,9
a = 0,2 mol; b = 0,15 mol => a: b = 4: 3
Cu 4: t chy hon ton m gam hn hp X gm hai este ng phn cn 6,272 lt O2(ktc), thu c 5,376 lt CO2(ktc) v 4,32 gam H2O. Thy phn hon ton m gam hn hp X bng lng va dd NaOH , Oxi ha hon ton ancol sinh ra ri cho sn phm to thnh T/d dd AgNO3/NH3 d thu c 23,76 gam Ag. Cc P xy ra hon ton. % khi lng hai este l
A. 62,5% v 37,5%
B. 60% v 40% C. 50% v 50% D. 70% v 30%
Hng Dn
p dng nh lut bo ton khi lng ( mX = 5,92 (g).
= = 0,24 (mol )( este no n chc, mch h (CnH2nO2).
Da vo phn ng t chy gii c n = 3, nX = 0,08 (mol).
CTPT: C3H6O2 ( CTCT ( x + y = 0,08 (*).
S hp thc: HCOOC2H5 ( C2H5OH ( CH3CHO ( 2Ag(
x 2x
CH3COOCH3 ( CH3OH ( HCHO ( 4Ag(
y 4y
(
2x + 4y = 0,22 (**).
Gii h (*) v (**), ta c: x = 0,05; y = 0,03.
hu c Z ; cn Y to ra CH2=CHCOONa v kh T. Cc cht Z v T ln lt l
TH4: Thy phn Este a chcCu 1: Hp cht hu c X cha C, H, O mch thng c phn t khi l 146. X khng T/d Na. Ly 14,6 gam X T/d 100ml dd NaOH 2M thu c 1 mui v 1 ru. CTCT X l:A. C2H4(COOCH3)2 B. (CH3COO)2C2H4 C. (C2H5COO)2 D. A v B ng Hng Dn
nX:nNaOH = 1:2 =>CT X: R(COOR)2 hoc (RCOO)2R
TH1: R + 2R = 58 => R = 28 (-C2H4) v R = 15 (-CH3)
TH2: 2R + R = 58 => R = 28 (-C2H4) v R = 15 (-CH3)
Cu 2: Thy phn hon ton 0,05 mol este ca 1 axit a chc vi 1 ancol n chc cn 5,6 gam KOH. Mt khc, khi thy phn 5,475 gam este th cn 4,2 gam KOH v thu c 6,225 gam mui. CTCT ca este l:
A. (COOC2H5)2B. (COOC3H7)2 C. (COOCH3)2D. CH2(COOCH3)2
Hng Dn
Thy phn 0,05 mol este ca 1 axit a chc vi 1 ancol n chc
P thy phn 5,475 gam
Cu 3: Este X c to thnh t etylen glycol v hai axit cacboxylic n chc. Trong phn t este, s nguyn t cacbon nhiu hn s nguyn t oxi l 1. Khi cho m gam X T/d vi dd NaOH (d) th lng NaOH P l 10 gam. Gi tr ca m l
A. 14,5.B. 17,5.C. 15,5.D. 16,5.Hng Dn
S nguyn t cacbon nhiu hn s nguyn t oxi l 1 nn c 4 nguyn t O th X c 5 C. Cng thc X l:
Cu 4: Cho 0,01 mol mt este X P va vi 100 ml dd NaOH 0,2 M, sn phm to thnh ch gm mt ancol Y v mt mui Z vi s mol bng nhau. Mt khc, khi x phng ho hon ton 1,29 gam este bng mt lng va l 60 ml dd KOH 0,25 M, sau khi P kt thc em c cn dd c 1,665 gam mui khan. CT ca este X l:
A. C2H4(COO)2C4H8 B. C4H8(COO)2C2H4 C. C2H4(COOC4H9)2 D. C4H8(COO C2H5)2
Hng Dn
Ta c: nZ = nY ( X ch cha chc este
S nhm chc este l: = = 2 ( CT ca X c dng: R(COO)2RR(COO)2R + 2KOH ( R(COOK)2 + R(OH)2T phn ng thy phn: naxit = nmui = nKOH = .0,06.0,25 = 0,0075 mol
( M mui = MR + 83.2 = = 222 ( MR = 56 ( R l: -C4H8-Meste = = 172 ( R + 2.44 + R = 172 ( R = 28 (-C2H4-)Vy X l: C4H8(COO)2C2H4 ( p n B.
Cu 5: Mt hp cht hu c X c CT C7H12O4. Bit X ch c 1 loi nhm chc, khi cho 16 gam X T/d va 200 gam dd NaOH 4% th thu c mt ancol Y v 17,8 gam hn hp 2 mui. Xc nh CTCT thu gn ca X.
A. CH3OOC-COOC2H5
B. CH3COO-( CH2)2-COOC2H5 C. CH3COO-(CH2)2-OCOC2H5
D. CH3OOC-COOCH3Hng Dn
p dng DDLBTKL tn khi lng Ancol
Cu 6: Cho 32,7 gam cht hu c X ch cha mt loi nhm chc T/d vi 1,5 lt dd NaOH 0,5M thu c 36,9 gam mui v 0,15 mol Ancol. Lng NaOH d c th trung ha ht 0,5 lt dd HCl 0,6M. CTCT ca X l
A. CH3COOC2H5
B. (CH3COO)2C2H4 C. (CH3COO)3C3H5
D. C3H5(COOCH3)3Hng Dn
PT T/d dd NaOH
Cu 7: un nng m gam hn hp X gm cc cht cng mt loi nhm chc vi 600 ml dd NaOH 1,15M c dd Y cha mui ca mt axit cacboxylic n chc v 15,4 gam hi Z gm cc ancol. Cho ton b Z T/d vi Na d, thu c 5,04 lt kh H2 (ktc). C cn dd Y, nung nng cht rn thu c vi CaO cho n khi P xy ra hon ton c 7,2 gam mt cht kh. Gi tr ca m l
A. 40,60 B. 22,60 C. 34,30 D. 34,51
Hng Dn
(R1COO)xR2 + x NaOH xR1COONa + R2(OH)x
0,45
0,45
0,45/x
R2(OH)x x/2 H2
0,45/x 0,225
RCOONa + NaOH Na2CO3 + RH
0,45 0,24 0,24
n ancol = 2n H2 = 0,45 mol
C n NaOH d = 0,6.1,15 0,45 = 0,24 mol
M kh = 7,2 : 0,24 = 30 => C2H6 => R1 = 29
Vy m = 0,45.96 + 15,4 0,45.40 = 40,6 gam
Chn A.
(RCOONa + NaOH => RH + Na2CO3)
Dng 4: Hiu sut P Este
Phn ng este ha:
RCOOH + ROH RCOOR + H2O
B/ a mol b mol
P/ x mol x mol x mol x mol
Sau p/ (a-x) mol (b-x) mol
1. Tnh hiu sut ca P este ha:
* Nu a b => H = xb . 100 => x = ; b =
* Nu a < b => H = xa . 100 => x = a =
2. Tnh hng s cn bng:
KC = Cu 1: un 12 gam axit axetic vi 1 lung d ancol etylic ( c H2SO4 c lm xc tc). n khi P dng li thu c 11 gam este. Hiu sut ca P este ho l bao nhiu
A. 70%B. 75%
C. 62,5%
D. 50%
Cu 2: Tnh khi lng este metyl metacrylat thu c khi un nng 215 gam axit metacrylat vi 100 gam ancol metylic. Gi thit P este ho t hiu sut 60%.
A. 125 gam
B. 175 gam
C. 150 gam
D. 200 gam
Cu 3: Khi un nng 25,8 gam hn hp ancol etylic v axit axetic c H2SO4 c lm xc tc thu c 14,08 gam este. Nu t chy hon ton lng hn hp thu c 23,4 ml H2O. Tm thnh phn trm mi cht trong hn hp u v hiu sut ca phn ng este ho.
A. 53,5% C2H5OH; 46,5% CH3COOH v hiu sut 80%
B. 55,3% C2H5OH; 44,7% CH3COOH v hiu sut 80%
C. 60,0% C2H5OH; 40,0% CH3COOH v hiu sut 75%
D. 45,0% C2H5OH; 55,0% CH3COOH v hiu sut 60%
Cu 4: un 12 gam axit axetic vi 13,8 gam etanol ( c H2SO4 c lm xc tc) n khi P t ti trng thi cn bng, thu c 11 gam este. Hiu sut ca P este ho l:
A. 55%
B. 50%
C. 62,5%
D. 75%
Cu 5: Khi thc hin P este ha 1 mol CH3COOH v 1 mol C2H5OH, lng este ln nht thu c l 2/3 mol. t hiu sut cc i l 90% (tnh theo axit). Khi tin hnh este ha 1 mol CH3COOH cn s mol C2H5OH l (bit cc P este ho thc hin cng nhit )
A. 2,115. B. 2,925.
C. 2,412. D. 0,456.
Hng Dn
CH3COOH + C2H5OH CH3COOC2H5 + H2O
Ban u 1 1 (mol)
P 2/3 2/3 2/3 2/3 (mol)
Cn bng 1/3 1/3 2/3 2/3
Ta c
Hiu sut cc i l 90% (tnh theo axit) (naxit p= 1.90%=0,9(mol)
CH3COOH + C2H5OH CH3COOC2H5 + H2O
Ban u 1 a (mol)
P 0,9 0,9 0,9 0,9 (mol)
Cn bng 0,1 (a 0,9) 0,9 0,9
Ta c
Cu 6: Hn hp X gm HCOOH v CH3COOH c s mol bng nhau. Ly 5,3 gam hn hp X cho T/d vi 5,75 gam C2H5OH (c H2SO4 c lm xc tc) thu c m gam hn hp este (hiu sut cc P este ha u bng 80%). Gi tr m l
A. 8,80B. 7,04C. 6,48D. 8,10
Hng Dn
RCOOH + C2H5OH RCOOC2H5 + H2O
B 0,1 0,125
Cu 7: Cho bit hng s cn bng ca phn ng este ho:
CH3COOH + C2H5OH CH3COOC2H5 + H2O KC = 4
Nu cho hn hp cng s mol axit v ancol T/d vi nhau th khi P t n trng thi cn bng th % ancol v axit b este ho l
A. 50%. B. 66,7%.
C. 33,3%. D. 65%.
Cu 8: Cho cn bng sau: CH3COOH + C2H5OH CH3COOC2H5 + H2O KC = 4
Khi cho 1 mol axit T/d vi 1,6 mol ancol, khi h t n trng thi cn bng th hiu sut ca P l
A. 66,67%. B. 33,33%.
C. 80%. D. 50%.
Cu 9: un nng hn hp X gm 1 mol ancol etylic v 1 mol axit axetic (c 0,1 mol H2SO4 c lm xt), khi P t n trng thi cn bng c hn hp Y trong c 0,667 mol etyl axetat. Hng s cn bng KC ca phn ng l
A. KC = 2. B. KC = 3.
C. KC = 4. D. KC = 5.
Cu 10: Bit rng P este ho CH3COOH + C2H5OH CH3COOC2H5 + H2O C hng s cn bng KC = 4, tnh % Ancol etylic b este ho nu bt u vi [C2H5OH] = 1M, [CH3COOH] = 2 M.
A. 80%
B. 68%
C. 75%
D. 84,5%
Cu 11: t chy hon ton 7,6 gam hn hp gm mt axit cacboxylic no, n chc, mch h v mt ancol n chc thu c 0,3 mol CO2 v 0,4 mol H2O. Thc hin P este ha 7,6 gam hn hp trn vi hiu sut 80% thu c m gam este. Gi tr ca m l
A. 4,08. B. 6,12. C. 8,16. D. 2,04.
Hng Dn
Do t axit no, n chc cho H2O = CO2 nn ancol cn tm l ancol no, n chc.
S mol ancol = 0,4 0,3 = 0,1 mol
S mol CO2 do ancol to ra s < 0,3 mol. Vy ancol A c mt hoc hai nguyn t C
TH1 Ancol c 1 nguyn t C vy ancol l CH3OH
S mol CO2 do axit to ra = 0,3 0,1 = 0,2 mol
Khi lng axit = 7,6 0,1.32 = 4,4 gam
CT axit : CnH2n+1COOH c s mol l x mol
Vy: (n+1).x = 0,2 v (14n+46)x = 4,4
Tm c: x = 0,05 v n = 3
Este: C3H7COOCH3 c s mol = 0,05.80% = 0,04 mol
Vy khi lng: 0,04.102 = 4,08 gam ( A.
TH2 Ancol c hai nguyn t C
Cu 12: Hn hp A gm axit axetic v etanol. Chia A thnh ba phn bng nhau.
+ Phn 1 T/d vi Kali d thy c 3,36 lt kh thot ra.
+ Phn 2 T/d vi Na2CO3 d thy c 1,12 lt kh CO2 thot ra. Cc th tch kh o ktc.
+ Phn 3 c thm vo vi git dd H2SO4, sau un si hn hp mt thi gian. Bit hiu sut ca P este ho bng 60%. Khi lng este to thnh l bao nhiu
A. 8,80 gam B. 5,20 gam C. 10,56 gam D. 5,28 gamHng Dn
Hn hp A ( (
V a < b (( hiu sut tnh theo axit) ( s mol este thc t thu c: n = 0,1.60% =
( Khi lng este thc t thu c: m = 0,06.88 = 5,28 gam ( p n D
Cu 13: Khi thu phn este A (khng T/d Na, c cu to mch thng di) trong mi trng axit v c c 2 cht hu c B v C. un 4,04 gam A vi dd cha 0,05 mol NaOH c 2 cht B v D. Cho bit MD = MC + 44. Lng NaOH d c trung ho bi 100 ml dd HCl 0,1M. un 3,68 gam B vi H2SO4 c, 170oC vi hiu sut 75% c 1,344 lit olfin (ktc). Tm CTCT A.
A. C3H5(OOCCH3)2.
B. C3H5(OOCC2H5)2.
C. C2H4(OOCCH3)2.
D. C4H8(COOC2H5)2Hng Dn
C: R(COOH)x ; D: R(COONa)x
67x 45x = 44 => x = 2
A: R(COOC2H5)2
R(COOC2H5)2 + 2 NaOH
0,02 0,04
MA = 202 => R = 56 (-C4H8)
A: C4H8(COOC2H5)2
Cu 14: Hn hp M gm ancol no, n chc X va axit cacboxylic n chc Y, u mach h v co cung s nguyn t C, tng s mol cua hai cht la 0,5 mol (s mol cua Y ln hn s mol cua X). Nu t chay hoan toan M thi thu c 33,6 lit khi CO2 (ktc) va 25,2 gam H2O. Mt khac, nu un nong M vi H2SO4 c thc hin P este hoa (hiu sut la 80%) thi s gam este thu c la
A. 34,20 B. 27,36 C. 22,80 D. 18,24Hng Dn
S C = nCO2/nhh = 3 vy ancol l C3H7OH 4H2O . V nNc < nCO2 nn axit khng no.
Axit c 3C c 2TH: CH2=CH-COOH 2H2O ; x + y = 0,5 v 4x + 2y = 1,4. Ta c x= 0,2 v y = 0,3 (nhn)
CHC-COOH 1H2O ; x + y = 0,5 v 4x + y = 1,4. Ta c x= 0,3 v y = 0,2 (loi nY < nX)
Este l CH2=CH-COOC3H7. Vi m CH2=CH-COOC3H7 = 0,2*0,8*114 = 18,24 (g)
C. L THUYT V BI TP LIPIT
LIPIT: Phn ln lipit l cc este phc tp, bao gm cht bo (triglixerit), sp, steroit v photpholipit,Trong chng trnh ta ch yu quan tm cht bo. CHT BO: Cht bo l trieste ca glixerol vi axit bo, gi chung l triglixerit hay l triaxylglixerol.
Cc axit bo hay gp:C17H35COOH hay CH3[CH2]16COOH: axit stearic
C17H33COOH hay cis-CH3[CH2]7CH=CH[CH2]7COOH: axit oleic
C15H31COOH hay CH3[CH2]14COOH: axit panmitic
( Axit bo l nhng axit n chc c mch cacbon di, khng phn nhnh, c th no hoc khng no.
CTCT chung ca cht bo:
R1, R2, R3 l gc hirocacbon ca axit bo, c th ging hoc khc nhau.
Th d v cht bo :
(C17H35COO)3C3H5: tristearoylglixerol (tristearin) (rn m)
(C17H33COO)3C3H5: trioleoylglixerol (triolein) (lng du)
(C15H31COO)3C3H5: tripanmitoylglixerol (tripanmitin) (lng du) Phn ng thu phn trong mi trng axit: Phn ng x phng ho(thy phn trong mi trng baz): Phn ng cng hiro ca cht bo lng
S trieste c to thnh t glixerol v n phn t Axit bo l:
S trieste =
Ch s axit: S mg KOH dung trung ha lng axit t do trong 1 g cht bo.
Ch s axit = (khng i dn v ml)
Tnh cht git ra:
1) c im cu trc phn t mui natri ca axit bo:
Cu to phn t mui natri ca axit bo gm:
Mt u a nc, -COONa.
Mt ui k nc , nhm CXHY
2) C ch hot ng ca cht git ra natri stearat: ui a du m CH3[CH2]16- thm nhp vo vt du bn, cn nhm COONa a nc li c xu hng ko ra pha cc phn t nc.Kt qu: Vt du b phn chia thnh cc ht rt nh gi cht bi cc phn t natri stearat, ri b ra tri.
Dng 5: Tnh khi lng cht bo hoc khi lng x phng
Ta c PTTQ: (RCOO)3C3H5 + 3 NaOH ( 3RCOONa +C3H5(OH)3
( cht bo) (X phng) ( glixerol)
p dng LBT KL: mcht bo + mNaOH = mx phng + mglixerol => m ca cht cn tm
Cu 1: Cho 40,3 gam Trieste X ca Glyxerol vi Axit bo T/d va vi 6 gam NaOH. S gam mui thu c l:
A. 38,1 gam B. 41,7 gam C. 45,6 gam D. 45,9 gam
Hng Dn
S mol NaOH = 6 : 40= 0,15 mol :
C3H5(O-OC- )3 + 3NaOH C3H5(OH)3 + 3 COONa
0,05 0,15 0,05 0,15 mol
40,3 6 0,05.92 m gam
Theo nh lut BTKL ta c: Khi lng mui COONa =40,3+6-0,05.92=41,7 gam.
Cu 2: t chy hon ton m gam cht bo (triglixerit) cn 1,61 mol O2, sinh ra 1,14 mol CO2 v 1,06 mol H2O. Cng m gam cht bo ny T/d va vi dd NaOH th khi lng mui to thnh l
A. 23,00 gam.B. 20,28 gam.C. 18,28 gam.D. 16,68 gam.
Hng Dn
nO/cht bo = 1,06+1,14*2 - 1,61*2= 0,12 mol suy ra ncht bo=0,02mol
mmui=mcht bo+0,06*40-0,02*92 =18,28.
Cu 3: Khi thy phn mt Lipit X ta thu c cc axit bo l Axit oleic, Axit panmetic, Axit stearic. t chy hon ton 8,6 gam X cn th tch O2(ktc) A. 16,128 lt B. 20,16 lt C. 17,472 lt D. 15,68 lt
Hng Dn
X c CTCT l
Cu 4: un nng 44,5 gam cht bo l triglixerit ca 1 axit hu c no vi 70 ml dd NaOH 20% (d=1,2g/ml). trung ho lng kim d cn 22,5ml HCl 36,5%(d=1,2g/ml).CTCT ca cht bo.
A.(C17H29COO)3C3H5
B.(C17H31COO)3C3H5
C.(C17H35COO)3C3H5
D.(C15H29COO)3C3H5Cu 5: Thy phn hon ton 444 gam mt lipit thu c 46g glixerol v hai loi axit bo.Hai loi axit bo l
A.C17H31COOH v C17H33COOH B. C15H31COOH v C17H35COOH
C. C17H33COOH v C17H35COOH D. C15H31COOH v C17H33COOH
Hng Dn
n glixerol = 0,5.
Triglixerit + 3H2O 3 RCOOH + Glixerol
1,5 1,5 0,5
Theo nh lut bo ton khi lng: m axit = 444 +1,5.18 46 = 425g
Vy M tb axit = 425: 1,5 = 283,3. phi c 1 a xit < 283,3 c th l C17H33COOH (282)hoc C17H31COOH ( 280) hoc C15H31COOH (256)v 1 a xit > 283,3 l C17H35COOH (284)
Nhng th li ch c :0,5.282 + 0,5.2.284 = 425 l hp l. Chn C.
Cu 6: un nng 7,2 gam este X vi dd NaOH d. P kt thc thu c glixerol v 7,9 gam hn hp mui. Cho ton b hn hp mui T/d vi H2SO4 long thu c 3 axit hu c no, n chc, mch h Y, Z, T. Trong Z, T l ng phn ca nhau, Z l ng ng k tip ca Y. CTCT ca X
A. B.
C. D.A hoc B
Hng Dn
V Y, Z l ng ng k tip v Z, T l ng phn ca nhau
( c th t cng thc chung ca este X: C3H5(OCO)3
C3H5(OCO)3 + 3NaOH ( 3COONa + C3H5(OH)3 (1)
Theo (1), ta c : nmui = 3neste (
( ( CTCT cc cht: ( p n DCu 7: Mt loi cht bo c cha 25% triolein ,25% tripanmitin v 50% tristearin v khi lng. Cho m Kg cht bo trn P va vi dd NaOH un nng, thu c 1 tn x phng nguyn cht. Gi tr ca m l
A. 972,75
B. 1004,2
C. 1032,33
D. 968,68Hng Dn
(C17H33COO)3C3H5 + 3NaOH ( 3C17H33COONa+ C3H5(OH)3 (M=884) (912)
(C15H31COO)3C3H5 + 3NaOH ( 3C16H33COONa+ C3H5(OH)3 (M=806) (834)
(C17H35COO)3C3H5 + 3NaOH ( 3C17H35COONa+ C3H5(OH)3 (M=890) (918)
Cu 8: Mt loi m cha 40% triolein, 20% tripanmitin v 40% tristearin (v khi lng).. X phng ha hon ton m gam m trn thu c 138 gam glixerol. Gi tr ca m l:
A. 1,326 kg B. 1,335 kg C. 1,304 kg D. 1,209 kg
Hng Dn
Cu 9: A l mt este to bi 3 chc mch h. un nng 7,9 gam A vi NaOH d thu c 9,6 gam mui D v Ancol B. Tch nc t B c th thu c propenal. Cho D T/d dd H2SO4 thu c 3 axit no n chc mch h, trong 2 axit c phn t khi nh l ng phn ca nhau. CTPT ca axit c phn t khi nh l
A. C5H10O2
B. C7H14O2
C. C4H8O2
D. C6H12O2
Hng Dn
- Ancol B tch nc c th thu c propenal. Vy B l Glixerol
- T/d dd NaOH
2 axit c phn t khi nh l ng phn ca nhau l C3H7COOH
Cu 10: Mt este X pht xut t anol A v axit B n chc 0,01 mol X (mX = 8,90 gam) P va vi 0,3 lt dd NaOH 0,1M cho ra ancol B v mui C (mC = 9,18 gam). Xc nh CTCT ca X.
A. C3H5(OOCC15H31)3.
B. C3H5(OOCC17H35)3.C. C3H5(OOCC17H33)3.
D. C3H5(OOCC15H29)3.
Cu 11: Cho 2,4 gam este X bay hi trong mt bnh kn dung tch 0,6 lt. Khi este bay hi ht th p sut trong bnh 136,50C l 425,6 mmHg. thy phn 25,4 gam X cn 0,3 mol NaOH thu c 28,2 gam mt mui duy nht. Xc nh CTCT ca X, bit rng X pht xut t ancol a chc.
A. C3H5(OOCCH3)3.
B. C3H5(OOCC2H5)3.
C. C2H4(OOCCH3)3.
D. C3H5(OOCCH = CH2)3.Dng 6: Ch s axit v ch s x phng
Ch s axt ca cht bo: L s miligam KOH cn trung ho lng axit bo t do c trong 1 gam cht bo.
Ch s axt =
Ch s x phng ho ca cht bo: l tng s miligam KOH cn trung ho lng axit t do v x phng ho ht lng este trong 1 gam cht bo Ch s x phng =
Cu 1: X phng ho hon ton 2,5 gam cht bo cn 50 ml dd KOH 0,1 M. Ch s x phng ho ca cht bo l:
A. 280
B. 140
C. 112
D. 224
Hng Dn
Ch s x phng =
Cu 2: trung ho 14 gam mt cht bo cn 15 ml dd KOH 0,1 M. Ch s axit ca cht bo l
A. 6
B. 5
C. 7
D. 8
Hng Dn
Ch s axt =
Cu 3: x phng ho hon ton 2,52 gam mt lipt cn dng 90 ml dd NaOH 0,1M. Tnh ch s x phng ca lipit
A. 100
B. 200
C. 300
D. 400
Cu 4: trung ho 15 gam mt loi cht bo c ch s axit bng 7, cn dng dd cha a gam NaOH. Gi tr ca a l
A. 0,150 B. 0,280 C. 0,075D. 0,200
Hng dn:
Cu 5: Cho 200 gam mt loi cht bo c ch s axit bng 7 T/d va vi mt lng NaOH, thu c 207,55 gam hn hp mui khan. Khi lng NaOH tham gia phn ng l:
A. 31 gamB. 32,36 gamC. 30 gamD. 31,45 gam
Hng dn:
Gi s mol NaOH ban u l a
(RCOO)3C3H5 (Chtbo) + 3NaOH 3RCOONa + C3H5(OH)3 (1)
RCOOH (t do) + NaOH RCOONa + H2O (2) 0,025 0,025 mol
Bo + KOH mui (x phng) + C3H5(OH)3 + H2O (3)
( Ch s axit l 7 nn s mol KOH dng trung ha axit l:
200.7.10-3/56 = 0,025mol = s mol NaOH
( s mol H2O to ra: 0,025 mol
( s mol NaOH phn ng vi trieste l : a 0,025 ( s mol glixerol thu c:
LBTKL: mX + m NaOH = m mui + mglixerol +
200 + 40a = 207,55 + 92 + 18 . 0,025 ( a = 0,775 ( m NaOH = 31 gam
Cu 6: x phng ho hon ton 50 gam cht bo c ch s axit l 7 cn 0,16 mol NaOH. Tnh khi lng glixerol thu c?
A. 9,43gam B. 14,145gam
C. 4,715gam
D. 16,7 gam
Hng dn:
(RCOO)3C3H5 (Chtbo) + 3NaOH 3RCOONa + C3H5(OH)3 (1)RCOOH (t do) + NaOH RCOONa + H2O (2)Bo
+ NaOH mui (x phng) + C3H5(OH)3 + H2O (3)Cn nm r cc khi nim
1. Ch s axit: l smg KOH (2)cn trung ho ht axit t do c trong 1 gam cht bo2. Ch s este: l smg KOH (1)cn thu phn ht este bo c trong 1 gam cht bo3. Ch s x phng = ch s axit + ch s este
4. Khi lng x phng thu c khi x phng ha.
p dng nh lut bo ton khi lng cho phng trnh s (3)
mbo + mKOH = mx phng + mnc + mglixerol mx phng = mbo + mKOH - mnc - mglixerol
Cu 7: X phng ha 1 kg cht bo c ch s axit bng 7 ,ch s x phng ha 200.Tnh khi lng glixerol thu c A. 9,43gam B. 14,145gam
C. 4,715gam
D. 105,7 gamHng dn
Ch s este ha = 200 - 7 = 193S mol KOH este ha = 1000*0,193/56 = 3,446429==> mol Glyxerol = mol KOH/3 = 1,14881==> khi lng glyxerol = 92*1,14881 = 105,7Cu 8:X phng ho hon ton 12,5 gam cht bo c ch s x phng l 224, thu c 13,03 gam mui( Gi thit gc axit trong este v axit t do l nh nhau). Ly ton b lng glyxerol sinh ra em iu ch thuc n trinitro glyxerat. Ch s axit v khi lng thuc n thu c l: A.6,5 v 5,942g B. 5,6 v 4,125g C. 5,6 v 5,942g D. p n khc
Hng dn
(RCOO)3C3H5 (Chtbo) + 3NaOH 3RCOONa + C3H5(OH)3 (1) 3a a
RCOOH (t do) + NaOH RCOONa + H2O (2) b b
nNaOH=3.22412,5.1039 = 0,05mol.gi s mol glyxerol=a v s mol H2O=b 3a + b = 0,05BTKL: mchatbeo + mNaOH = mmuoi + mglyxerol + mH2O
12,5+0,05.40=13,03+92a+18ba=0,015 va`b=0,005Ch s axit:0,005.56.100012,5=22,4Thuc n l:C3H5(ONO2)3m=0,015.227=3,405 gamCu 9:Mt cht bo l trieste ca mt a xit v a xit t do cng l a xit cha trong cht bo.Ch s x phng ca cht bo l 208,77 v ch s a xit l 7.Cng thc Axit trong 1gam cht bo l
A. Stearic B.Oleic C. panmitic D. linoleic
Hng dn:
208,77mg = 0,20877g 0,003728mol KOH
7mg = 0,007g 0,000125mol KOH
(RCOO)3C3H5 + 3KOH 3RCOOK + C3H5(OH)3 0,001201 0,003603
RCOOH + KOH RCOOK + H2O
0,000125 0,000125
Bi cho: 0,001201.(3R +173) + 0,000125.(R+45) = 1
=>R= 211 vy a xit l 211+45 =256:panmitic =>Chn C.
Cu 10: x phng ha 100 kg cht bo c ch s axit l 7 cn dd cha 14,18 kg NaOH.Khi lng x phng cha 28% cht ph gia thu c l
A.143,7kg B. 14,37kg C. 413,7kg D.41,37kg
Hng dn:
nNaOH = 14180:40 = 354,5mol
n NaOH cn trung ha a xit bo d trong 100 kg l: 0,125.100 = 12,5 mol.
=> nNaOH x phng ha l: 354,5 -12,5= 342mol
(RCOO)3C3H5 + 3NaOH 3RCOONa + C3H5(OH)3 342 114
RCOOH + NaOH RCOONa + H2O
12,5 12,5
Theo nh lut bo ton khi lng c 2phng trnh:
mcht bo + mNaOH = mmui + m glixerol + m H2O
mmui = 100000 + 14180 114.92 12,5.18 =103467g
mx phng = 103467.100/72 = 143704,16g =143,7kg
Chn A.
Cu 11: x phng ho 35 kg triolein cn 4,939 kg NaOH thu c 36,207 kg x phng. Ch s axit ca mu cht bo trn l:
A. 7
B. 8 C. 9 D. 10
Hng Dn
Theo bi: nRCOONa (x phng) =
( nNaOH (dng x phng ho) = 119,102 mol
( nNaOH ( trung ho axit bo t do) =
( nKOH ( trung ho axit bo t do) = 4,375 mol
( mKOH (trong 1 g cht bo) =
( ch s axit = 7 ( p n A
Cu 12: Mt loi cht bo c ch s x phng ho l 188,72 cha axit stearic v tristearin. trung ho axit t do c trong 100 g mu cht bo trn th cn bao nhiu ml dung dch NaOH 0,05 M
A. 100 ml B. 675 ml C. 200 ml D. 125 ml
Hng Dn
axp = 188,72.10-3 ( phn ng vi 100 g cht bo cn mKOH = 188,72.10-3 .100 = 18,872 g
( nKOH = ( nNaOH = 0,337 mol
( (
Vy: Trong 100 g mu cht bo c 0,01 mol axit t do ( nNaOH (p) = 0,01 mol
( Vdd NaOH = 200 ml ( p n C
B- BI TP
(T d n kh)
Bi 1: Cho este C3H6O2 x phng ho bi NaOH thu c mui c khi lng bng 41/37 khi lng este. Tm CTCT ca este.
HD: RCOOR
Suy lun: Do este n chc m mmui > meste nn gc R < 23 nn CT este CH3COOCH3
Chi tit: Ta c: => (este n chc nn s mol cc cht bng nhau)
=> MRCOONa = = 82 => R = 15 => R = 15
CT: CH3COOCH3
Bi 2: Tm CTCT ca este C4H8O2 bit rng khi tc dng ht vi Ca(OH)2 thu c mui c khi lng ln hn khi lng ca este.
HD: 2RCOOR + Ca(OH)2 (RCOO)2Ca + 2R(OH)
a a/2
bi ra ta c: (2R + 88 +40)a/2 > (R + R + 44)a => R < 20 (-CH3)
CTCT: CH3CH2COOCH3Bi 3: Cho vo bnh kn (c V = 500 ml) 2,64 gam mt este A hai ln este ri em nung nng bnh n 273C cho n khi ton b este ha hi th p sut trong bnh lc ny l 1,792 atm. Xc nh CTPT
ca A
HD: => 12x+y = 68 => C5H8O4
Bi 4: un nng 0,1 mol cht hu c X vi mt lng va dung dch NaOH thu c 13,4 gam mui ca mt axit hu c Y v 9,2 gam mt ru. Cho ru bay hi 127C v 600 mmHg thu c mt th tch 8,32 lt. CTCT ca X l:
A. C2H5OOC COOC2H5
B. CH3OOC-COOC2H5
C. CH3OOC-CH2-COOC2H5
D. C2H5OOC CH2 COOC2H5
HD:
nru = 0,2 => Mru = 46 => C2H5OH
nru = 2 nX nn este phi l este ca axit hai chc v ru n chc c dng: R(COOC2H5)2 R(COOC2H )2 + 2NaOH 2C2H5OH + R(COONa)2
0,2 0,1
Mmui = 134 => R = 0 => A
Bi 5: Cho cc cht HCOOCH3; CH3COOH; CH3COOCH=CH2; HCOONH4; CH3COOC(CH3)=CH2; CH3COOC2H5; HCOOCH2-CH=CH2. Khi cho cc cht trn tc dng vi dd NaOH thu c sn phm c kh nng tc dng vi dd AgNO3/NH3. S cht tho mn iu kin trn l: A. 3 B. 4 C. 5 D. 6
HD: HCOOCH3; CH3COOCH=CH2; HCOONH4; HCOOCH2-CH=CH2
Bi 6: Cho 12,9g mt este n chc, mch h tc dng ht vi 150ml dd KOH 1M. Sau phn ng thu c mt mui v anehit. S CTCT ca este tho mn tnh cht trn l:
A. 1 B. 2 C. 3 D. 4
HD: HCOOCH=CH-CH3 v CH3COOCH=CH2
Bi 7: Hp cht hu c X cha C, H, O mch thng c phn t khi l 146. X khng tc dng Na. Ly 14,6g X tc dng 100ml dd NaOH 2M thu c 1 mui v 1 ru. CTCT X l:
A. C2H4(COOCH3)2 B. (CH3COO)2C2H4 C. (C2H5COO)2 D. A v B ng
HD nX:nNaOH = 1:2 =>CT X: R(COOR)2 hoc (RCOO)2R
TH1: R + 2R = 58 => R = 28 (-C2H4) v R = 15 (-CH3)
TH2: 2R + R = 58 => R = 28 (-C2H4) v R = 15 (-CH3)
Bi 8: Cho 21,8 gam cht hu c A ch cha 1 loi nhm chc tc dng vi 1 lt dung dch NaOH 0,5M thu c 24,6 gam mui v 0,1 mol ru. Lng NaOH d c th trung ha ht 0,5 lt dung dch HCl 0,4M. Cng thc cu to thu gn ca A l:
HD:Theo bi ra => (RCOO)3R
Theo pt => nmui = 0,3
Mmui = 24,6/0,3 = 82 MRCOONa = 82 =>R = 15 MA = 21,8/0,1= 218
3(15 + 44) + R = 218 R = 41 CT ca este l: (CH3COO)3C3H5
Bi 9: X l mt cht hu c n chc c M = 88. Nu em un 2,2 gam X vi dung dch NaOH d, thu c 2,75 gam mui. Cng thc cu to thu gn ca cht no sau y ph hp vi X:
A. HCOOCH2CH2CH3.
B. CH3CH2CH2COOH.
C. C2H5COOCH3.
D. HCOOCH(CH3)2.
* Nhn xt: Vi lp lun X l cht hu c no, n chc, phn ng vi dung dch NaOH nn X l axit hoc este (loi kh nng l phenol v Mphenol 94 > 88 ( = 94)).
Bi 10: un 20,4 gam mt hp cht hu c n chc A vi 300 ml dung dch NaOH 1M thu c mui B v hp cht hu c C. Khi cho C tc dng vi Na d cho 2,24 lt kh H 2 (ktc). Bit rng khi un nng mui B vi NaOH (xt CaO, t) thu c kh K c t khi i vi O2 bng 0,5. C l hp cht n chc khi b oxi ha bi CuO (t) cho sn phm D khng phn ng vi dung dch AgNO3 /NH3 da. CTCT ca A l:
A. CH3COOCH2CH2CH3
B. CH3COOCH(CH3)CH3
C. HCOOCH(CH3)CH3
D. CH3COOCH2CH3
b. Sau phn ng gia A v NaOH thu c dung dch F. C cn F c m(g) hn hp cht rn. Tnh m.
HD: a. Suy lun:
MK = 16 l CH4 nn axit to este l CH3COOH este c dng CH3COOR
D khng phn ng vi dung dch AgNO3 /NH3 d => D l xeton
=> cu B
Chi tit: este c dng CH3COOR
V este n chc: neste = nru = 2nH 2 = 0,2
=> 15+44+R = 102 => R = 43 ( -C3H7)
D khng phn ng vi dung dch AgNO3 /NH3 d => D l xeton
=> cu B
b. m = mCH3COONa + mNaOH d = 20,4
Bi 11: Hp cht hu c X c thnh phn C, H, O v ch cha 1 nhm chc trong phn t. un nng X vi NaOH th c X1 c thnh phn C, H, O, Na v X2 c thnh phn C, H, O. MX1 = 82%MX; X2 khng tc dng Na, khng cho phn ng trng gng. t 1 th tch X2 thu c 3 th tch CO2 cng iu kin. Tm CTCT X
HD: D dng nhn ra X l este.
Theo bi ra thy X2 l xeton v c 3C: CH3-CO-CH3
X: RCOO-C(CH3)=CH2 ; X1: RCOONa
C: R + 67 = 0,82(R + 85) => R = 15
Vy X: CH3-COO-C(CH3)=CH2Bi 12: Hn hp X c khi lng m(g) cha mt axit n chc no Y v mt ru n chc no Z cng s nguyn t cacbon vi Y. Chia hh X thnh 3 phn bng nhau.
Phn 1: Cho tc dng vi Na d thu c 2,8 lt H2 (ktc)
Phn 2: em t chy hon ton c 22g CO2 v 10,8g H2O
a. X CTPT ca Y v Z.
b. Tm m
c. un nng phn 3 vi H2SO4 c thu c 7,04g este. Tnh hiu sut phn ng este ho.
HD: nCO2 = 0,5; nH2O = 0,6
Do axit v ancol n chc nn: nX = 2nH2 = 0,25
s nguyn t C: = nCO2/nhh = 0,5/0,25 = 2
a. CH3COOH v C2H5OH
b. C: nru = nH2O nCO2 = 0,1 (do axit no th nCO2 = nH2O)
naxit = 0,15 => m = 13,6g
c. h = 80%
Bi 13: Thc hin phn ng x phng ho cht hu c X n chc vi dung dch NaOH thu c mt mui Y v ancol Z. t chy hon ton 2,07 gam Z cn 3,024 lt O2 (ktc) thu c lng CO2 nhiu hn khi lng nc l 1,53 gam. Nung Y vi vi ti xt thu c kh T c t khi so vi khng kh bng 1,03. CTCT ca X l:
A. C2H5COOCH3B. CH3COOC2H5C. C2H5COOC3H7D. C2H5COOC2H5
Gii :
- Theo bi: X n chc, tc dng vi NaOH sinh ra mui v ancol ( X l este n chc: RCOOR.
Mt khc: mX + = + ( 44.+ 18.= 2,07 + (3,024/22,4).32 = 6,39 gam
V 44.- 18.= 1,53 gam ( = 0,09 mol ; = 0,135 mol
> ( Z l ancol no, n chc, mch h c cng thc: CnH2n+1OH (n 1)
nZ = nH2O nCO2 => MZ = 46 (C2H5OH)
MT = 30 => C2H6 p n D
Bi 14: Hn hp X gm 2 cht A, B mch h, u cha cc nguyn t C, H, O v u khng tc dng Na. Cho 10,7g hh X tc dng va NaOH ri c cn sn phm thu c phn rn gm 2 mui natri ca 2 axt n chc no ng ng lin tip v phn hi bay ra ch c mt ru E duy nht. Cho E tc dng vi Na d thu c 1,12lt H2 (ktc). Oxi ho E bng CuO un nng v cho sn phm c th tham gia phn ng trng gng.
a. Tm CTCT ca E bit dE/KK = 2
b. Tm CTCT A, B bit MA < MB
HD: a. ME = 58 => E: C3H6O : CH2=CH-CH2OH (ru allylic)
b. Theo bi ra A, B l 2 este n chc, ng ng lin tip: COOC3H5
nX = nru = 2nH2 = 0,1 => MX = 107 => = 22
A: CH3COOCH2-CH=CH2
B: C2H5COOCH2-CH=CH2
Bi 15: Hn hp A gm 2 cht hu c X, Y u no, n chc v tc dng vi NaOH (MX > MY). T khi hi ca A so vi H2 l 35,6. Cho A td hon ton vi dd NaOH thy ht 4g NaOH, thu c 1 ru n chc v hh 2 mui ca 2 axit n chc. Cho ton b lng ru thu c td vi Na d c 672 ml H2 (ktc). Tm CTPT X, Y.
HD: nA = nNaOH = 0,1 ; nru = 2nH2 = 0,06
Ta thy X, Y n chc m nru < nNaOH nn hh A gm: X l axit (CxH2xO2) v Y l este (CyH2yO2)
nY = nru = 0,06 => nX = 0,1 0,06 = 0,04
mA = 71,2. 0,1 = 7,12 = (14x + 32)0,04 + (14y + 32)0,06
0,56x + 0,84y = 3,92
Vi x>y 2 => x = 4, y = 2
CTPT: C4H8O2 v C2H4O2
Bi 16: Khi thu phn este A (khng tc dng Na, c cu to mch thng di) trong mi trng axit v c c 2 cht hu c B v C. un 4,04g A vi dd cha 0,05 mol NaOH c 2 cht B v D. Cho bit MD = MC + 44. Lng NaOH cn d c trung ho bi 100ml dd HCl 0,1M. un 3,68g B vi H2SO4 c, 170oC vi hiu sut 75% c 1,344 lit olfin (ktc). Tm CTCT A.
HD: nNaOH d = 0,01 => nNaOH p A = 0,04
d dng tm c B: C2H5OH
Suy lun:C l axit; D l mui natri
mt khc MD = MC + 44 => axit 2 chc => nA = nNaOH = 0,02MA = 202 => R = 56 (-C4H8)
A: C4H8(COOC2H5)2
chi tit: C: R(COOH)x ; D: R(COONa)x
67x 45x = 44 => x = 2
A: R(COOC2H5)2
R(COOC2H5)2 + 2 NaOH
0,02 0,04
MA = 202 => R = 56 (-C4H8)
A: C4H8(COOC2H5)2
Bi 17: t chy hon ton 6,8 gam mt este A no n chc cha vng benzen thu c CO2 v H2O . Hp th ton b sn phm ny vo bnh ng dung dch Ca(OH)2 ly d thy khi lng bnh tng 21,2 gam ng thi c 40 gam kt ta. Xc nh CTPT, CTCT c th c ca A
A. 2
B. 3
C. 4
D. 5
HD: Tm CTG: D dng tm c CTPT C8H8O2
4CTCT: phenyl axetat; 3 p: o, m, p -metyl phenyl fomat
Bi 18: Hn hp X gm 1 ancol no, n chc v 1 axit no, n chc mch h. Chia X thnh 2 phn bng nhau.
- t chy hon ton phn 1 sn phm thu c cho qua bnh nc vi trong d thy c 30g kt ta.
- Phn 2 c este ho hon ton va thu c 1 este, t chy este ny thu c khi lng H2O l:
A. 1,8g B. 3,6g C. 5,4g D. 7,2g
HD:
Suy lun: Ta thy s C trong este bng tng C trong axit v ancol => Kh t este v hh (axit, ancol) th thu c CO2 nh nhau.
Mt khc t este no, n chc c nH2O = nCO2 = 0,3
Chi tit:
CnH2n+1OH nCO2
CmH2m+1COOH (m+1)CO2
CmH2m+1COOCnH2n+1(n+m+1) H2O
phn ng va => nax = nancol = x => nCO2 = (n+m+1)x = 0,3
t este: nH2O = (n+m+1)x = 0,3 => C
Bi 19: Thu phn hon ton m gam este X n chc bng NaOH thu c mui hu c A v ancol B. Cho B vo bnh Na d thy khi lng bnh tng 3,1g v c 1,12 lt kh (ktc) thot ra. Mt khc cng cho m gam este X phn ng va 16g brom thu c sn phm cha 35,1% brom theo khi lng. CTCT ca X:
A. C15H33COOCH3
B. C17H33COOCH3
C. C17H31COOCH3
D. C17H33COOC2H5
HD: Ta c: mB = 3,1 + = 3,2
neste = nru = 2nH2 = 0,1 => R = 15 (-CH3)
LBTKL: mg X + 16g Br2 (m + 16)g SP
Ta c: => m = 29,6 => Meste = 296 => R = 237 (-C17H33)
Bi 20: Mt este n chc E c dE/O2 = 2,685. Khi cho 17,2g E tc dng vi 150ml dd NaOH 2M sau c cn c 17,6g cht rn khan v 1 ancol. Tn gi ca E l:
A. Vinyl axetat B. anlyl axetat C. Vinyl fomiat D. Anlyl fomiatHD: nNaOH p = nE = 0,2
=> mmui = 17,6 40(0,3-0,2) = 13,6 => R = 1 => R = 41
Bi 21: Mt hn hp X gm 2 este n chc thy phn hon ton trong mi trng NaOH d cho hn hp Y gm 2 ru ng ng lin tip v hn hp mui Z
- t chy hn hp Y th thu c CO2 v hi H2O theo t l th tch 7:10
- Cho hn hp Z tc dng vi lng va axit sunfuric c 2,08 gam hn hp A gm 2 axit hu c no. Hai axit ny va phn ng vi 1,59 gam natricacbonat
Xc nh CT ca 2 este bit rng cc este u c s nguyn t cacbon < 6 v khng tham gia phn ng vi AgNO3/NH3.
HD: C: RCOOR RCOONa RCOOH + Na2CO3
0,03 0,015
t Y: nH2O > nCO2 => CH2 +1OH T ti l => = 2,33
=> 2 ru l: C2H5OH v C3H7OH (1)
axit = 2,08/0,03 = 69,3 => = 24,3 (2)
Do C < 6 v kt hp (1),(2) => C2H5COOC2H5 v CH3COOC3H7 (khng c phn ng vi AgNO3/NH3).
Bi 22: Mt este A (khng cha chc no khc) mch h c to ra t 1 axit n chc v ru no. Ly 2,54 gam A t chy hon ton thu c 2,688 lt CO2 (ktc) v 1,26 gam H2O . 0,1 mol A phn ng va vi 12 gam NaOH to ra mui v ru. t chy ton b lng ru ny c 6,72 lt CO2 (ktc). Xc nh CTPT, CTCT ca A
HD: nA:nNaOH = 1:3
(RCOO)3R + 3NaOH 3RCOONa + R(OH)3 0,1 0,1
s nguyn t cacbon ca ru: n = 0,3/0,1 = 3 => C3H5 (OH)3Khi t chy A => CTG: C6H7O3 . V este 3 chc => CTPT A: C12H14O6 = 254
Ta c: 3(R1 + 44) + 41 = 254 R1= 27 CH2 CHVy A: (C2H3COO)3C3H5
Bi 23: un nng 0,1 mol este no, n chc mch h X vi 30 ml dung dch 20% (D = 1,2 g/ml) ca mt hiroxit kim loi kim A. Sau khi kt thc phn ng x phng ho, c cn dung dch th thu c cht rn Y v 4,6 gam ancol Z, bit rng Z b oxi ho bi CuO thnh sn phm c kh nng phn ng trng bc. t chy cht rn Y th thu c 9,54 gam mui cacbonat, 8,26 gam hn hp CO2 v hi nc. Cng thc cu to ca X l:
A. CH3COOCH3
B. CH3COOC2H5
C. HCOOCH3
D. C2H5COOCH3
Gii :
X l este no, n chc, mch h : CnH2n+1COOCmH2m+1 ( 0 ( n; 1 ( m)
Ta c: nX = nAOH (p) = nZ = 0,1 mol ( MZ = 14m + 18 = = 46 ( m = 2
Mt khc:
nA = = 2.( MA = 23 ( A l Na ( nNaOH (ban u) =
Y
EMBED Equation.3
EMBED Equation.3Vy: mY + =
Hay 0,1(14n+68) + 0,08.40 + = 9,54 + 8,26 ( n = 1 ( X : CH3COOCH3 ( p n A
Bi 24: Mt hn hp A gm 2 este n chc X, Y (MX < My). un nng 12,5 gam hn hp A vi mt lng dung dch NaOH va thu c 7,6 gam hn hp ancol no B, n chc c khi lng phn t hn km nhau 14 vC v hn hp hai mui Z. t chy 7,6 gam B thu c 7,84 lt kh CO2 (ktc) v 9 gam H2O. Phn trm khi lng ca X, Y trong hn hp A ln lt l:
A. 59,2%; 40,8%B. 50%; 50%C. 40,8%; 59,2%C. 66,67%; 33,33%
Bi gii :
T bi ( A cha 2 este ca 2 ancol ng ng k tip
t cng thc chung ca ancol l
= 7,84/22,4 = 0,35 mol; = 9/18 = 0,5 mol ( nB = -= 0,5 0,35 = 0,15 mol
( = = 2,33. Vy B
t cng thc chung ca hai este l ( neste = nNaOH = nmui = nY = 0,15 mol
( mZ = 12,5 + 0,15.40 7,6 = 10,9 g ( = + 67 = =72,67 ( = 5,67
Nh vy trong hai mui c mt mui l HCOONa
Hai este X, Y c th l:
(I) hoc (II)
- trng hp (I) (
- trng hp (II) ( 12x + y = 8 ( loi)
Vy A( n n A
Bi 25: un nng 7,2 gam este X vi dung dch NaOH d. Phn ng kt thc thu c glixerol v 7,9 gam hn hp mui. Cho ton b hn hp mui tc dng vi H2SO4 long thu c 3 axit hu c no, n chc, mch h Y, Z, T. Trong Z, T l ng phn ca nhau, Z l ng ng k tip ca Y. Cng thc cu to ca X l:
A. B.
C. D.A hoc B
Gii :
V Y, Z l ng ng k tip v Z, T l ng phn ca nhau
( c th t cng thc chung ca este X: C3H5(OCO)3
(1) C3H5(OCO)3 + 3NaOH ( 3COONa + C3H5(OH)3Theo (1), ta c : nmui = 3neste (
( ( CTCT cc cht: ( p n DBi 26: Cho 0,01 mol mt este X ca axit hu c phn ng va vi 100 ml dung dch NaOH 0,2 M, sn phm to thnh ch gm mt ancol Y v mt mui Z vi s mol bng nhau. Mt khc, khi x phng ho hon ton 1,29 gam este bng mt lng va l 60 ml dung dch KOH 0,25 M, sau khi phn ng kt thc em c cn dung dch c 1,665 gam mui khan. Cng thc ca este X l:
A. C2H4(COO)2C4H8B. C4H8(COO)2C2H4C. C2H4(COOC4H9)2D. C4H8(COO C2H5)2
Gii:
Ta c: nZ = nY ( X ch cha chc este
S nhm chc este l: = = 2 ( CT ca X c dng: R(COO)2RT phn ng thy phn: naxit = nmui = nKOH = .0,06.0,25 = 0,0075 mol
( M mui = MR + 83.2 = = 222 ( MR = 56 ( R l: -C4H8-Meste = = 172 ( R + 2.44 + R = 172 ( R = 28 (-C2H4-)Vy X l: C4H8(COO)2C2H4 ( p n B.
Bi 27: Hn hp A gm axit axetic v etanol. Chia A thnh ba phn bng nhau.
+ Phn 1 tc dng vi Kali d thy c 3,36 lt kh thot ra.
+ Phn 2 tc dng vi Na2CO3 d thy c 1,12 lt kh CO2 thot ra. Cc th tch kh o ktc.
+ Phn 3 c thm vo vi git dung dch H2SO4, sau un si hn hp mt thi gian. Bit hiu sut ca phn ng este ho bng 60%. Khi lng este to thnh l bao nhiu?
A. 8,80 gamB. 5,20 gamC. 10,56 gamD. 5,28 gam
Bi gii:
Hn hp A ( (
V a < b (( hiu sut tnh theo axit) ( s mol este thc t thu c: n = 0,1.60% =
( Khi lng este thc t thu c: m = 0,06.88 = 5,28 gam ( p n D
Bi 28: t chy hon ton 1 mol axit cacboxylic n chc X cn 3,5 mol O2. Trn 7,4 gam X vi lng ancol no Y (bit t khi hi ca Y so vi O2 nh hn 2). un nng hn hp vi H2SO4 lm xc tc. Sau khi phn ng hon ton thu c 8,7 gam este Z (trong Z khng cn nhm chc no khc). Cng thc cu to ca Z l:
A. C2H5COOCH2CH2OCOC2H5B. C2H3COOCH2CH2OCOC2H3
C. CH3COOCH2CH2OCOCH3D. HCOOCH2CH2OCOH
Bi gii:
Phn ng chy: CXHyO2 + (x + -1)O2 ( xCO2 + H2O (1)
Theo (1), ta c : x + -1= 3,5 ( x + = 4,5 ( ( X : C2H5COOH
Ancol no Y : CnH2n+2-m (OH)m (1 ( m ( n) ( este Z : (C2H5COO)mCnH2n+2-m
( Meste = 73m + 14n + 2 m = hay 14n + 2 = 15m (2)
Mt khc < 2 hay 14n + 2 + 16m < 64 ( 30m + 2 < 64 (v m ( n) ( m < 2,1
T (2) ( ( ancol Y : C2H4(OH)2
( Z : C2H5COOCH2CH2OCOC2H5 ( p n A.
Bi 29: t chy hon ton mt lng hn hp hai este X, Y, n chc, no, mch h cn 3,976 lt oxi (ktc) thu c 6,38 gam CO2. Cho lng este ny tc dng va vi KOH thu c hn hp hai ancol k tip v 3,92 gam mui ca mt axit hu c. Cng thc cu to ca X, Y ln lt l
A. C2H5COOC2H5 v C2H5COOC3H7B. C2H5COOCH3 v C2H5COOC2H5
C. CH3COOCH3 v CH3COOC2H5D. HCOOC3H7 v HCOOC4H9
Bi gii :
t cng thc trung bnh ca 2 este X, Y l: CnH2n+1COO
V X, Y u l este n chc, no, mch h nn: = = 6,38/44 = 0,145 mol
( meste + = 44. + 18. ( meste = 3,31 gam
neste = nCO2 + 1/2nH2O nO2 = 0,04 mol
( nmui = neste = 0,04 mol ( Mmui = 14n + 84 = 3,92/0,04 = 98 ( n = 1
Mt khc: = 3,31/0,04 = 82,75 ( 12.1 + 46 + 14 = 82,75 ( = 1,77
Vy: X l CH3COOCH3 v Y l CH3COOC2H5 ( p n C
Bi 30: t chy 0,8 gam mt este X n chc c 1,76 gam CO2 v 0,576 gam H2O. Cho 5 gam X tc dng vi lng NaOH va , c cn dung dch sau phn ng c 7 gam mui khan Y. Cho Y tc dng vi dung dch axit long thu c Z khng phn nhnh. Cng thc cu to ca X l:
A. B. C. D. CH2=CH-COOC2H5Bi gii :
Cng thc X: CxHyO2 ( 2 ( x; y ( 2x )
Theo bi: mc = gam; mH = gam ( mO (X) = 0,256 gam
( x : y : 2 = 0,04 : 0,064 : 0,016 = 5 : 8 : 2
( Cng thc ca X: C5H8O2
V X l este n chc (X khng th l este n chc ca phenol) ( nX = nY = nz = nNaOH = 0,05 mol
Ta c : mX + mNaOH (p) = 5 + 0,05.40 = 7 gam = mmui Y
( E l este mch vng ( p n C
Bi 31: Hn hp A gm ba cht hu c X, Y, Z n chc ng phn ca nhau, u tc dng c vi NaOH. un nng 13,875 gam hn hp A vi dung dch NaOH va thu c 15,375 gam hn hp mui v hn hp ancol c t khi hi so vi H2 bng 20,67. 136,50C, 1 atm th tch hi ca 4,625 gam X bng 2,1 lt. Phn trm khi lng ca X, Y, Z (theo th t KLPT gc axit tng dn) ln lt l:
A. 40%; 40%; 20%B. 40%; 20%; 40%C. 25%; 50%; 25%D. 20%; 40%; 40%
Bi gii :
Ta c : ( MX =
Mt khc: X, Y, Z n chc, tc dng c vi NaOH ( X, Y, Z l axit hoc este
( CTPT dng: CxHyO2, d dng (
Vy A ( ( ( p n BBi 32: trung ho 14g cht bo X cn 15ml dd KOH 0,1M. Ch s axit ca cht bo l?
HD: mKOH = 0,015.0,1.56 = 0,084g = 84mg KOH
14g cht bo...............84mg KOH
Vy 1g cht bo.................6 mg KOH => ch s axit l 6
Bi 33: trung ho 10g cht bo c ch s axit l 5,6 th khi lng NaOH cn dng l bao nhiu?
HD: 0,04g
Bi 34: x phng ho hon ton 2,52g mt lipit cn dng 90ml dd 0,1M. Tnh ch s x phng ho ca lipit?
HD: 200
Bi 35: thu phn hon ton 8,58Kg mt loi cht bo cn va 1,2Kg NaOH, thu c 0,368kg glixerol v hh mui ca axit bo. Bit mui ca cc axit bo chim 60% khi lng x phng. Khi lng x phng c th thu c l:
HD: 15,69kg
Bi 36: trung ho 14g cht bo X cn 15ml dd KOH 0,1M. Ch s axit ca cht bo l?
HD: mKOH = 0,015.0,1.56 = 0,084g = 84mg KOH
14g cht bo...............84mg KOH
Vy 1g cht bo.................6 mg KOH => ch s axit l 6
Bi 37: x phng ho 35 kg triolein cn 4,939 kg NaOH thu c 36,207 kg x phng. Ch s axit ca mu cht bo trn l:
A. 7
B. 8
C. 9
D. 10
Bi gii :
Theo bi: nRCOONa (x phng) = ( nNaOH (dng x phng ho) = 119,102 mol
( nNaOH ( trung ho axit bo t do) =
( nKOH ( trung ho axit bo t do) = 4,375 mol
( mKOH (trong 1 g cht bo) =
( ch s axit = 7 ( p n A
Bi 38: Mt loi cht bo c ch s x phng ho l 188,72 cha axit stearic v tristearin. trung ho axit t do c trong 100 g mu cht bo trn th cn bao nhiu ml dung dch NaOH 0,05 M
A. 100 ml
B. 675 ml
C. 200 ml
D. 125 ml
Bi gii :
axp = 188,72.10-3 ( phn ng vi 100 g cht bo cn mKOH = 188,72.10-3 .100 = 18,872 g
( nKOH = ( nNaOH = 0,337 mol
( (
Vy: Trong 100 g mu cht bo c 0,01 mol axit t do ( nNaOH (p) = 0,01 mol
( Vdd NaOH = 200 ml ( p n CBI TP TRONG THI
Bi 1: X l mt este no n chc, c t khi hi i vi CH4 l 5,5. Nu em un 2,2 gam este X vi dung dch NaOH (d), thu c 2,05 gam mui. Cng thc cu to thu gn ca X l: (khi B 2007)
A. C2H5COOCH3.B. HCOOCH2CH2CH3.C. CH3COOC2H5D. HCOOCH(CH3)2.
Gii:
Meste = 5,5.16 = 88 neste = 2,2/88 = 0,025 mol
( nEste = nmui = 0,025 mol ( Mmui = 2,05/0,025 = 82
( R=82 67 = 15 ( R l CH3- ( p n C ng
* Ch : Ta c th dng phng php loi tr tm p n:
T bi: meste > mmui ( X khng th l este ca ancol CH3OH ( p n A loi.
T phn ng thy phn ta ch xc nh c CTPT ca cc gc R v R m khng th xc nh c cu to ca cc gc do B v D khng th ng thi ng do ta loi tr tip B v D.
Vy ch c p n C ph hp
Bi 2: C=10: Hn hp Z gm hai este X va Y tao bi cung mt ancol va hai axit cacboxylic k tip nhau trong day ng ng (MX < MY). t chay hoan toan m gam Z cn dung 6,16 lit khi O2 (ktc), thu c 5,6 lit khi CO2 (ktc) va 4,5 gam H2O. Cng thc este X va gia tri cua m tng ng la
A. CH3COOCH3 va 6,7 B. HCOOC2H5 va 9,5
C. HCOOCH3 va 6,7 D. (HCOO)2C2H4 va 6,6
HD: Gii : => X, Y l 2 este no n chc
p dng LBTKL : m = + 4,5 - = 6,7 (gam)
t cng thc ca X, Y : => =>
=> => n = 2 ; n = 3 X : C2H4O2 HCOOCH3 Y : C3H6O2 CH3COOCH3
Ch : gp bi ton hu c m khi t chy th cn bao nhiu lt oxi hoc cn tnh th tch oxi th chng ta nn ngh ngay n pp LBTKL hoc LBTNT ty thuc vo d kin bi ton cho.
Bi 3: C10: Thuy phn cht hu c X trong dung dich NaOH (d), un nong, thu c san phm gm 2 mui va ancol etylic. Cht X la
A. CH3COOCH2CH3 B. CH3COOCH2CH2Cl
C. ClCH2COOC2H5 D. CH3COOCH(Cl)CH3
HD: ClCH2COOC2H5 + 2NaOH NaCl + HO-CH2COONa + C2H5OHBi 4: C10: t chay hoan toan 2,76 gam hn hp X gm CxHyCOOH, CxHyCOOCH3, CH3OH thu c 2,688 lit CO2 (ktc) va 1,8 gam H2O. Mt khac, cho 2,76 gam X phan ng va u vi 30 ml dung dich NaOH 1M, thu c 0,96 gam CH3OH. Cng thc cua CxHyCOOH la
A. C2H5COOH B.CH3COOH C. C2H3COOH D. C3H5COOH
HD: + Axit v este u khng no (CH3OH chy cho s mol H2O ln hn s mol CO2) loi A, B
+ = amol
Cch 1: neste = 0,03-a. Ta c: nCO2 = (x+1)a + (x+2)(0,03-a) + a = 0,12 => x = 2
Cch2: Coi X gm CxHyCOOCH3 v H2O Vi neste mi = 0,03 mol
p n C
Bi 5: C10: Cho 45 gam axit axetic phn ng vi 69 gam ancol etylic (xc tc H2SO4 c), un nng, thu c 41,25 gam etyl axetat. Hiu sut ca phn ng este ho l
A. 62,50% B. 50,00%C. 40,00% D. 31,25%
HD: %
Bi 6: C10: trung ho 15 gam mt loi cht bo c ch s axit bng 7, cn dng dung dch cha a gam NaOH. Gi tr ca a l
A. 0,150 B. 0,280 C. 0,075 D. 0,200
HD:
Cch khc:
thi C H ch c 1 cu v ch s axit v cn nh cng thc tnh th bi ton tr nn nh nhng hn nhiu,
Bi 7: HB-2011: Cho 200 gam mt loi cht bo c ch s axit bng 7 tc dng va vi mt lng NaOH, thu c 207,55 gam hn hp mui khan. Khi lng NaOH tham gia phn ng l:
A. 31 gamB. 32,36 gamC. 30 gamD. 31,45 gam
Hng dn: cu ny tng t thi C 2010 chc cc bn lm thun thc ri
( s mol NaOH phn ng vi trieste l : a 0,025 ( s mol glixerol thu c:
ADLBTKL
Bi 8: C11: phn ng ht vi mt lng hn hp gm hai cht hu c n chc X v Y (Mx < MY) cn va 300 ml dung dch NaOH 1M. Sau khi phn ng xy ra hon ton thu c 24,6 gam mui ca mt axit hu c v m gam mt ancol. t chy hon ton lng ancol trn thu c 4,48 lt CO2 (ktc) v 5,4 gam H2O. Cng thc ca Y l :
A. CH3COOC2H5 B. CH3COOCH3 C. CH2=CHCOOCH3 D. C2H5COOC2H5HD: nancol =nH2O-nCO2 => C = nCO2/nancol => C2H5OH
V X, Y n chc m nNaOH > nancol => Y l este; X l axit (do Mx < MY v c cng gc axit)Mmui = 24,6/0,3 = 82 => R =-CH3
=> A
Bi 9: C11: Cho m gam cht hu c n chc X tc dng va vi 50 gam dung dch NaOH 8%, sau khi phn ng hon ton thu c 9,6 gam mui ca mt axit hu c v 3,2 gam mt ancol. Cng thc ca X l:
A. CH3COOC2H5B. C2H5COOCH3C. CH2=CHCOOCH3 D. CH3COOCH=CH2Bi 10: C11: x phng ho hon ton 52,8 gam hn hp hai este no, n chc , mch h l ng phn ca nhau cn va 600 ml dung dch KOH 1M. Bit c hai este ny u khng tham gia phn ng trng bc. Cng thc ca hai este l
A. CH3COOC2H5 v HCOOC3H7B. C2H5COOC2H5 v C3H7COOCH3
C. HCOOC4H9 v CH3COOC3H7D. C2H5COOCH3 v CH3COOC2H5Bi 11: C11: Hp cht hu c X c cng thc phn t l C4H8O3. X c kh nng tham gia phn ng vi Na, vi dung dch NaOH v phn ng trng bc. Sn phm thu phn ca X trong mi trng kim c kh nng ho tan Cu(OH)2 to thnh dung dch mu xanh lam. Cng thc cu to ca X c th l:
A. CH3CH(OH)CH(OH)CHOB. HCOOCH2CH(OH)CH3
C. CH3COOCH2CH2OH.D. HCOOCH2CH2CH2OH
HD: - X c phn ng vi dung dch NaOH, trng bc loi A, C
- Sn phm thu phn ca X trong mi trng kim c kh nng ho tan Cu(OH)2 to thnh dung dch mu xanh lam (tnh cht ru a chc c 2 nhm OH k nhau) => B
Bi 12: C11: Este X no, n chc, mch h, khng c phn ng trng bc. t chy 0,1 mol X ri cho sn phm chy hp th hon ton vo dung dch nc vi trong c cha 0,22 mol Ca(OH)2 th vn thu c kt ta. Thu phn X bng dung dch NaOH thu c 2 cht hu c c s nguyn t cacbon trong phn t bng nhau. Phn trm khi lng ca oxi trong X l:
A. 43,24%B. 53,33%C. 37,21%D. 36,26%
HD: Cn nCO2
0,1 0,1n
CO2 + Ca(OH)2 CaCO3 + H2O (1)
0,22 0,22 0,22
CO2 + CaCO3 + H2O Ca(HCO3)2 (2)
0,22 0,22
Theo (1), (2): thu c kt ta th: nCO2 < 0,22+0,22 = 0,44
Hay: 0,1n < 0,44 => n < 4,4
X + NaOH to 2 cht c C = nhau => X c 2 hoc 4 C
X khng c p trng gng => n = 4 C4H8O2
HA -2011
Bi 13: HA -2011 : t chy hon ton 3,42 gam hn hp gm axit acrylic, vinyl axetat, metyl acrylat v axit oleic, ri hp th ton b sn phm chy vo dung dch Ca(OH)2 (d). Sau phn ng thu c 18 gam kt ta v dung dch X. Khi lng X so vi khi lng dung dch Ca(OH)2 ban u thay i nh th no?
A. Tng 2,70 gam.B. Gim 7,74 gam.C. Tng 7,92 gam.D. Gim 7,38 gam.
Gii:
Cch 1: Sau phn ng thu c 18 gam kt ta th Khi lng X so vi khi lng dung dch Ca(OH)2 ban u s gim ri, vn l gim 7,74 hay 7,38 gamCng thc chung ca cc cht trn l CnH2n-2O2 do nu gi x l mol CO2, y l mol H2O
BTKL : 3,42 + 3/2y.32 = 44x + 18y . mt khc x = 0,18 ----> y = 0,18 ---> tng (CO2+H2O) =10,62< 18 gam kt ta nn dd gim 7,38gam => D ng.
Cch 2: hn hp gm axit acrylic, vinyl axetat, metyl acrylat v axit oleic u c ctc l:
. p dng lbt khi lng v nguyn t ta c:
Khi lng X so vi khi lng dung dch Ca(OH)2 ban u s gim l:
=> D ng.
Ch : ta lun c mCO2 + mH2O = mCaCO3 m(dd gim)
Bi 14: HA -2011: Cho axit salixylic (axit o-hiroxibenzoic) phn ng vi anhirit axetic, thu c axit axetylsalixylic (o-CH3COO-C6H4-COOH) dng lm thuc cm (aspirin). phn ng hon ton vi 43,2 gam axit axetylsalixylic cn va V lt dung dch KOH 1M. Gi tr ca V l
A. 0,72.B. 0,48.C. 0,96.D. 0,24.
Gii: 1mol axit axetylsalixylic (o-CH3COO-C6H4-COOH) th cn 3 mol KOH, nn d dng suy ra
=> A ng.
Nu cha hiu th theo cch gii sau: ptpu xy ra:
o-CH3COO-C6H4-COOH + 3KOH = CH3COOK +o-KO-C6H4-COOK+ 2H2O (1)
theo (1) => A ng.
Phn tch: cu ny nu khng cho sn phm v ctct ca axit axetylsalixylic th mc s kh hn nhiu, nhng cho ctct th nhn vo s tnh ra ngay. nu khng cn thn th s chn p n B: 0,48 lt.
Bi 15: HA -2011: Este X c to thnh t etylen glicol v hai axit cacboxylic n chc. Trong phn t este, s nguyn t cacbon nhiu hn s nguyn t oxi l 1. Khi cho m gam X tc dng vi dung dch NaOH (d) th lng NaOH phn ng l 10 gam. Gi tr ca m l
A. 14,5.B. 17,5.C. 15,5.D. 16,5.
Gii:
Cch 1. Cu ny bn phi tnh to th d dng suy ra cng thc ESTE l C5H8O4 (132)
Nu vn kh hiu th xem hng dn sau.
Cch 2. S nguyn t cacbon nhiu hn s nguyn t oxi l 1 nn c 4 nguyn t O th X c 5 C. cng thc X l:
Cch 3. (-COO)2C2H4 ( = 1 ( HCOOH v CH3COOH ( ME = 132
nNaOH = 0,25 ( nX = 0,125 ( m = 132.0,125 = 16,5 gam
Bi 16: HA -2011 : Cho dy cc cht: phenylamoni clorua, benzyl clorua, isopropyl clorua, m-crezol, ancol benzylic, natri phenolat, anlyl clorua. S cht trong dy tc dng c vi dung dch NaOH long, un nng l
A. 4.B. 3. C. 6.D. 5.
Gii: phenylamoni clorua, benzyl clorua, isopropyl clorua, m-crezol, anlyl clorua
Bi 17: HA -2011: t chy hon ton 0,11 gam mt este X ( to nn t mt axit cacboxylic n chc v mt ancol n chc) thu c 0,22 gam CO2 v 0,09 gam H2O. S este ng phn ca X l:
A. 2B. 5C. 6D.4
Gii:
Cch 1: theo quy lut ng phn ca este l: 1-2-4-9. nh vy ch c A hoc D ng m thi. m cho 0,11 gam nn D ng. v C2H4O2 (60) c 1 p este.
C3H6O2 (74) c 2 p este.
C4H8O2 (88) c 4 p este.
C5H10O2 (102) c 9 p este.
Ch : ly 0,11 chia cho 60, 74, 88... p n c s mol p th ta chon thi.
Cch 2: = 0,005 = ( Este no, n chc CnH2nO2 ( M = 14n + 32
n = 0,005 ( n = 4 ( S p este CnH2nO2 = 2n-2 => D ng.Bi 18: HB -2011: Cho dy cc cht: phenyl axetat, anlyl axetat, metyl axetat, etyl fomat, tripanmitin. S cht trong dy khi thy phn trong dung dch NaOH (d), un nng sinh ra ancol l:
A. 4B. 2C. 5D. 3Hng dn: bn phi thuc tt c cc cht hu => Ch c CH3COOC6H5 thy phn to 2 mui
Bi 19: HB -2011: Cho 200 gam mt loi cht bo c ch s axit bng 7 tc dng va vi mt lng NaOH, thu c 207,55 gam hn hp mui khan. Khi lng NaOH tham gia phn ng l:
A. 31 gamB. 32,36 gamC. 30 gamD. 31,45 gam
Hng dn: cu ny tng t thi C 2010 chc cc bn lm thun thc ri
( s mol NaOH phn ng vi trieste l : a 0,025 ( s mol glixerol thu c:
ADLBTKL
thi C H ch c 1 cu v ch s axit v cn nh cng thc tnh th bi ton tr nn nh nhng hn nhiuBi 20: HB -2011: Khi cho 0,15 mol este n chc X tc dng vi dung dch NaOH (d), sau khi phn ng kt thc th lng NaOH phn ng l 12 gam v tng khi lng sn phm hu c thu c l 29,7 gam. S ng phn cu to ca X tha mn cc tnh cht trn l:
A. 4B. 5C. 6D. 2
Hng dn: k thut bm my tnh: =>A ng.C1. p dng nh lut BTKL => C 4 ng phn. => A ng.
Nu khng hiu lm th xem cch sau.
Cch 2: nNaOH:nEste = 2:1 l este to bi axit v gc ancol dng phenol RCOOR + 2NaOH RCOONa + RONa + H2O 0,15 0,3 0,15
mEste = 29,7 + 0,15.18 12 = 20,4 gam MX = 136 = R + 44 R = 92 ( C7H8
( CTPT C8H8O2 ( ng phn ca X: CH3-COO-C6H5; HCOOC6H4 CH3 (c 3 p )Bi 21: HB -2011: Triolein khng tc dng vi cht (hoc dung dch) no sau y? A. H2O (xc tc H2SO4 long, un nng)B. Cu(OH)2 ( iu kin thng)
C. Dung