ncert q2

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Give an example of heterogeneously catalysed reaction? 1

2. What is the oxidation number of Ni in [Ni(CO)4]? 1

3. Give the IUPAC name of the following compound

1

4. Account the following:

o-nitrophenol has lower boiling point than p-nitrophenol. 1

5. Why are primary amines are higher boiling than tertiary amines? 1

6. Name the purines present in DNA. 1

7. Write formulae of the monomers of polythene and Teflon? 1

8. Why is bithional is added to the toilet soap? 1

9. An element having bcc structure with a cell edge of 288pm. If the density of the element

is 7.2g/cm3, what is atomic mass of the element? 2

10. Explain the following terms with suitable example:

i) F-centres ii) Schottky defect. 2

11. Molarity or molality, which is the best method to express concentration of a solution?

Why? 2

12. How much electricity in terms of Faraday is required to produce,

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i) 20 g of Ca from molten CaCl2?

ii) 50 g of Al from Al2O3? 2

13. Which is more basic La(OH)3 or Lu(OH)3? Why? 2

14. a) Use valance bond theory predict the geometry and magnetic behaviour of [Co(NH3)6]+3

ion .[At.No. of Co= 27]

b) Write the IUPAC name of [Pt(NH3)2Cl2] 2

15. Define the following terms:

a) Recemic mixture b) Resolution c) Enantiomers 2

16. What happens when: (Give chemical reactions)

a) Cyclohexanol is treated with Thionyl chloride?

b) p-Hydroxybenzyl alcohol is heated with HCl? 2

17. Distinguish between the terms homopolymer and co polymer and give an example of each. 2

18. What do you understand by broad spectrum antibiotics? Give one example. 2

19. At 300K, 36g of glucose ( C6H12O6) present per liter in its aqueous solution has an osmotic pressure of 4.98 bars. If the osmotic pressure of another solution of glucose is 1.52 bar at the same temperature, what would be its concentration? 3

20. Write the Nernst equation. Calculate e.m.f of the following cell at 250C:

Pt(s)/Br2(l)/Br-(0.010M)//H+(0.030M)/H2 (1 bar)/Pt(s) [Given: Eo Br2/Br- = +1.08 V] 3

21. a) Why is alum added to water for purification?

b) Explain why deltas are formed where river and sea water meet.

c) Describe the preparation of a colloidal solution of arserous sulphide in water. 3

22. Outline the principles of refining of metals by the following methods:








i) Zone refining ii) Electrolytic refining iii) Vapour phase refining. 3

23. a) Assign reasons for the following observations:

i) Hydrogen iodide is a stronger acid than hydrogen fluoride in aqueous solution.

ii) The basic character among the hydrides of Group 15 elements decreases with increasing

atomic numbers.

iii) Draw the structural formula for XeOF4. 3

24. Complete the following reaction equations:

i) Cr2O7-2 + Sn+2 +H+ -->

ii) MnO4- + Fe+2 +H+ -->

25. a) Give chemical test to distinguish between phenol and ethanol in seemingly similar

conditions.

b) Write the reaction equation for what happens when teritiory butyl alcohol is heated

with reduced copper at about 573K. 3

26. Write one chemical equation to exemplify the following reactions:

a) Carbylamine reaction

b) Hofmann bromamide reaction. 3

27. Define the following terms:

i) Co-enzymes

ii) Mutation in biomolecules

iii) Nucleotides. 3








28. a) Mention the factors that affect rate of a chemical reaction.

b) A first order reaction takes 69.3 minutes for 50% completion. Set up an equation for determining the time required for 80% completion of this solution.

c) Show that in a first order reaction, time required for completion of 99.9% is 10 times of half-life (t1/2) of the reaction. 5

29. Account for the following:

a) PH3 is a weaker base than NH3.

b) SF6 exists but SH6 does not.

c) ClF3 exists but FCl3 does not.

d) H3PO3 is diprotic acid.

e) ICl more reactive than I2. 5

30. a) An organic compound with the molecular formula C9H10O forms 2,4-DNP derivative,

reduces Tollen’s reagent and undergoes Cannizaro reaction. On vigorous oxidation,

it gives 1,2-benzene dicarboxylic acid. Identify the compound.

b) Write the steps and conditions involved in the following conversions:

i) Acetophenone to 2-phenyl-2-butanol.

ii) Propene to acetone. 5

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Guess Paper – 2011Class – XII

Subject – Chemistry

PREBOARD Time: 3 hrs..

General instructions:All questions are compulsory.Marks for each question are indicated against it.Questions number 1to 8 are very short –answer questions, carrying 1 mark each. Answer these in one word or about one sentence each.Questions number9 to18 are short –answer questions, carrying 2 marks each. Answer these in about 30 words each.Questions number19 to27 are short –answer questions, carrying 3 marks each. Answer these in about 40 words each.Questions number28 to30 are long-answer questions of 5 marks each. Answer these in about 70 words each.

1 Refractive index of a solid is observed to have the same value along all directions. Comment on the nature of this solid. Would it show cleavage property?

2 What kind of adsorption is represented by the following graph : (1)

T

x

M

3 Give one method of preparation of nitrous oxide. (1)4 What do you understand by ‘chelate ligand5 What is Saytzeff rule? (1)6 How will you convert Methyl iodide to Dimethylamine7 Why are primary amines higher boiling than tertiary amines? 8 Illustrate with equations, how is nylon obtained from caprolactum? 9 The vapour pressure of dilute aqueous solution of glucose (C6H12O6) is 750 mm of mercury at 373K. Calculate1) Molality2) Mole fraction of the solute (2)








10 Iron and Silver are used to make electrochemical cell by using a salt bridge to join a half cell containing 0.01

M Fe2+ (aq) in which a strip of iron has been immersed to a second half cell which contains 0.1 M Ag2+ (aq) in which a strip of Ag has been immersed ? A voltmeter is connected between the two metal strips:

E°Fe²+/Fe = – 0.44 V E°Ag²+/Ag = + 0.80 V

(a) Write the name of the cathode and anode.(b)Calculate the emf of cell

11 30% of a first order reaction was completed in 90 minutes. Calculate the time taken for the reaction to go to 90% completion? (2)12 A metal complex having the molecular formula Cr(NH3)4Cl2Br has been isolated in the two forms A and B.

A+AgNO3white ppt soluble in dilute aqueous ammonia B+ AgNO3Pale yellow ppt insoluble in dilute ammonia.

(i) Write the formula of the complexes A and B.(ii) What is the hybridisation of the chromium in both complexes? (2)

13 Apply VSEPR theory to deduce the structures of XeF4 and XeF6. (2)14 Write name reactions:

(i) Dow’s process (ii) Kolbe’s synthesis (2)15 Give reasons:

(i) Phenols do not undergo reactions involving cleavage of COH bond.(ii) Preparation of C2H5Cl is preferred with SOCl2 rather than PCl5 and PCl3. (2)

16 What is PHBV? Write its preparation. (2)17 Write two reactions of glucose with different reagents to confirm the presence of aldehydic group and secondary alcoholic group. (2)18 What are anomers ? Give two points of difference between two anomers of glucose. (2)19 What are defects? Give a brief account of defects. (3)20 75.2 g of phenol is dissolved in a solvent in which it undergoes association. Kf = 14, if the depression in freezing point is 7 K. What is the % association of phenol ? (3)21 Chromium metal can be plated out from acidic solution containing CrO3 according to following reaction- [At mass of Cr=52]

Calculate the mass of chromium that will be plated out by 12000 C of charge. (3)

22 Classify and explain different types of colloids. (3)23 (a)What are the factors which affect rate of reaction? (b) What is pseudo first order reaction? (2+1)

24 What is hydrometallurgy? Explain with the help of Mac Aurthur Forrest cyanide process. (3)25 (i) Arrange in order of property indicated : CH3CH2CH2CH2Br, (CH3)3 Br, (CH3)3 CHCH2 Br (Increasing boiling point)

(ii)CH3F, CH3I, CH3Cl, CH3Br (nucleophilic substitution)(iii) What is racemisation? (1+1+1)

26 Accomplish the following conversions :-------------------------------------------------------------------------------------------------------

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(i) Nitrobenzene to benzoic acid(ii) Benzyl Chloride to 2-phenylethanamine(iii)Write method used for preparing pure primary amines. (1+1+1)27 (a) What are barbiturates ? To which class of drugs do they belong ?(b) Why are cimetidine or ranitidine better antacids than sodium bicarbonate ormagnesium or aluminium hydroxide ?©Why is the use of aspartame limited to cold foods and drinks ? (1+1+1)28 Account for the following:

(i) Zn, Cd and Hg are not considered as transition elements.(ii) Scandium is a transition element but Zinc is not.(iii) Silver atom has completely filled d orbital (4d10) in its ground state, yet it is transition element(iv) Transition metals have high melting and boiling points.(v) Transition elements exhibit higher enthalpies of atomization. (5)

ORDescribe how Potassium dichromate is made from Chromite ore. Give the equations for the Chemical reactions involve. (b) Write balanced ionic equations for reacting ions to represent the action of acidified Potassium dichromate solution on:(i) Potassium iodide solution [ii] iron (II) solution [iii] H2S (c) The chromates and dichromates are interconvertible in aqueous solution depending upon pH of the solution. (5)29 (a) Primary alkyl halide C4H9Br (a) reacted with alcoholic KOH to give compound (b).Compound (b) is reacted with HBr to give (c) which is an isomer of (a).When (a) is reacted with sodium metal it gives Compound (d),C8H18 which is different from the compound formed when n-butyl bromide is reacted with sodium .Give the structural formula of (a) and write the equations for all the reactions. (b) An organic compound ‘A’ with molecular formula C5H5O . It does not reduce Tollen’s or Fehling’s reagent but forms a bisulphite compound. It also gives iodoform tests. Identify A

OR(a)An organic compound ‘A’ with molecular formula C5H8O2 is reduced to n-pentane on treatment with Zn-Hg/HCI. ‘A’ forms a dioxime with hydroxylamine and gives a positive iodoform test and Tollen’s test. Identify the compound A and deduce its structure.(b) An aromatic compound A on treatment with aqueous ammonia and heating forms compound B which on heating with Br2 and KOH forms a compound C of molecular formula C6H7N .Write the structures and IUPAC names of compounds A,B,C. 30 Explain:(a) why PCl3 fumes in air?(b) Why oxygen does not show +6 state?(c) Why higher concentration of O3 are explosive?(d) Why Cl2 act as bleaching agent?(e) How is xenon trioxide is prepared. Draw its structure? OR








(i) Why all the bonds in PCl5 are not of equal length?(ii) Why H2S is less acidic than H2Se ?(iii) How is O3 estimated quantitatively?(iv) Why fluorine has lower electron gain enthalpy than chlorine?(v) SF6 is highly stable.

Sample Paper – 2011Class – XII

Subject –ChemistryTIME ; 3HR First book

Selected Question

1) ALL QUESTION ARE COMPOLSORY2) USE LOG TABLE IF NECESSARY

Q.1 FILL THE BLANKS

1. XeF6+NaF -----

2. Zn+V.DIL HNO3 ----

3.SCl2+NAF ----

4.POCl3+H2O ----

P4O10

5.HNO3 ---HEAT--------

Q.2 GIVE THE METHIOD OF PREP.OF XeOF4 & XeO3 FROM XeF6

Q.3 DRAW THE STRUCTURE OF 1)H2SO5 2)H2S2O8

3)HOClO3 4) BrF3 5)XeF6

Q.4 GIVE THE ANSWER OF FOLL:

1) NOBAL GAS ELEMENT FROM COMPOUND WITH ONLY FLOURIN & OXYGEN

2) WHY ALL BOND IN PCL5 ARE NOT EQUAL IN LENGTH-------------------------------------------------------------------------------------------------------








3) OZONE IN THERMODYNAMICALLY UNSTABLE ?

4) HOW IS THE PRESENCE OF SO2 IS DETECTED ?

5) GIVE TWO IMP. USE OF NOBAL GAS.

Q.5 GIVE THE ANSWER OF FOLL

1) DESCRIBE THE MANUFACTHRING OF H2SO4 BY CONTACT PROCESS?

2) WHY DOES R3P=0 EXIST BUT R3N=0 DOES NOT ?

3) HOW RED PHOSPHOROUS IS OBTAINED FROM WHITE PHOSPHORUS ?

4) SF4 CAN BE HYDROLYS BUT SF6 CAN NOT ?

5) O3 ACT AS POWER OXIDISING AGENT

6) GIVE REASON, WHICH PREMPTED BARTTLET TO PREPARE 1ST NOBAL GAS COMPOUND.


1) FLOURINE DOES NOT SHOW VARIABLE O.S WHILE OTHER MEMBER OF HALOGEN FAMILY EXHIBIT VARIABLE O.S

2) HF IS STORED IN GLASS BOTTLE BUT IS KEPT IN WAX BOTTLE.

Q.7 EXPLAIN WITH REASON

1) THE ENTHALPY OF ATOMISATION OF T.M ARE HIGH2) CHEMISTRY OF ALL THE LANTHANOIDS IS QUITE SIMILAR3) CRO4

2- IS STRONG OXIDIZING AGENT WHILE MNO42- IS NOT

Q.8 GIVE REASON :

1) CE4+ IS USED AS OXIDISING AGENT IN VOLUMETRIC ANALYSIS.-------------------------------------------------------------------------------------------------------








2) INIDICTE THE STEPS FOR THE PREPERATION OF:

A) K2 CR2 O7 FROM ITS ORE CHROMITE ORE

B) KMNO4 FROM PYROLUSITE ORE


1) COMPARE THE CHEMISTRY OF THE ACTINOIDES WITH LANTHANOIDS WITH REFRENCE TO A) E - CONF B) OXIDATION STATE C) CHEMICAL STATE

2) T.M EXHIBITS HIGHEST O.S IN OXIDE & FLUORIDES?

3) NAME A MEMBER OF LANTHANOID SERIES WHICH IS WELL KNOWN TO EXHIBIT +4 O.S


1) K2[PTCL6] IS A WELL KNOUS COMP. WHERE AS THE CORSPENDING NI,COMP. IS NOT KNOWN GIVE REASON FOR IT

2) MN(II) SHOW MAX. PARAMAGNETIC CHARACTER AMONG DIVALENT ION OF 1ST T. SERIES WHY

3)WHAT ARE MISCH METALS GIVE EXAMPAL.


1) COMPAIRE THE FOLL COMPLEX WITH RESPECT TO STRUCTURAL SHAPE OF UNIT ,MAGNETIC BEHAVIOUR & HYBRID ORBITAL INVOLVED IN UNIT [ NICL4]-2, [CO(CN)6]3-

2) GIVE EXAMPALE & DEFINE

A) CHILATE B) LINKAGE ISOMERISM








3) WHY IS THE COMPLAX [TI(H2O)6]3+ ION IS COLOURED EXPLAIN ON THE BASIS OF ELECTRON IN THE D-ORBITALS

4) WHY IS THE GEO. ISOMERISM NOT POSSIBLE IN TETRAHEDRAL COMPLEXES HAVING TWO DIFFERENT TYPE OF UNIDENTATED LEGANDS COORDINATED WITH THE CENTRAL METAL ION

5)WRITE IUPAC NAME OF A) [Ni(NH3)6]Cl2 B) [CO(NH3)4(H2O)Cl]Cl2

C) [COCl2(CN)2]CL

Q.12

DISCUSS THE SPLITING OF AT ORBITAL IN OCTAHEDRAL AND

TETRAHEDRAL COMPLEXES.

Q.13 DEFINE:

1) HOMOLEPTIC & HETEROLEPTIC COMPLEX , AMBIDENTATE LEGEND

2) GIVE EVIDENCE THAT [CO(NH3)5Cl]SO4, [CO(NH3)5SO4] Cl ARE IONISATION ISOMERS

3) DISCUS THE ROLE OF COORDINATION COMP. IN

A) BIOLOGICAL SYSTEM B) ANALYTICAL CHEM.

4)DISCUSS NATURE OF BONDING IN METAL CARBONYL?


1) OUT OF C & CO WHICH IS THE BETTER REDUCING AGENT

2) WRITE CHEMICAL REACTION TAKING PLACE IN THE EXTRACTION OF ZINC FROM BLENDE.

3) WHY COPPER MATTE IS PUT IN SILICA LINED CONVERTOR

4)WHAT DO YOU MEAN THE TERM PYROMETALLURGY.-------------------------------------------------------------------------------------------------------








5) DESCRIBE THE UNDERLYING PRINCIPAL OF EACH OF FOLL

A) LIQUATION B) DISTILLATION C) VAPOUR PHARE REFINIG

D) ELECTROLYTIC REFINING E) ZONE REFINING

6) STATE THE ROLE OF SILICA IN THE METALLUREGY OF COPPER?

7) WHAT IS THE SIGNIFICANCE OF LEACHING IN EXTRACTION OF AL.

8) ROLE OF DEFRESSENT IN FROTH FLOATATION PROCESS


1) CLASSIFIED THE COLLOIDS ON THE BASIS OF

A) NATURE OF DISPERSION MEDIUM

B) INTERACTION BETWEEN DISPERSED PHASE & DISPERSION MEDIUM

2) A) SHAPE SELECTIVE CATALYSIS , ELECTROPHORESIS

B) COMMENT ON THE STATEMENT THAT COLLOID IS NOT SUBSTANCE BUT IS THE STATE OF SUBSTANCE

C) EXPLAIN WHAT IS OBSERVED

A) WHEN A BEAM OF LIGHT IS PASSED THROUGH COLLIDAL SOLUTION.

B) AN ELECTROLYTE , NACL IS ADDED TO HYDEATED FERRIC OXIDE SOL

C) ELECTRICAL CURRENT PASSED THROUGH

COLLIDAL SOL.

Q GIVE THE ANSWER OF FOLL

A) DIFFERENCE BETWEEN MULTIMOLECULAR & MACROMOLECULAR

COLLID & HOW ASSOCIATED COLLOIDS DIFFER FROM THESE TWO

TYPE OF COLLOIDS

B) DEFINE CRAFT TEMP & C.M.C








C) MANAFUCTURING OF HNO3 BY OSWALD PROCESS


A) WHY IS ADSORPTION ALWAYS EXOTERMIC ?

B) WHAT IS THE DIFFRENCE BET . A SOL & A GEL ?

C) STATE HARDY SCHULZE RULE ?

D) WRITE FREUNDLICH ISOTHERM EQUATION AT LAW PRESSURE ?

E) HOW YOUN CAN PREPARE AS2S3SOL & AU SOL & FE(OH) SOL

BY CHEMICAL METHOD

F) DESCRIBE SOME FEATRES OF CATALYSIS BY ZEOLITES ?

G) ROLE OF DESOPTION IN THE PROCESS OF CATALYSIS ?


A) RATE OF CHEMICAL REACTION DOUBLES FER AN INCREASE OF 10K IN ABSOLUTE TEMP. FROM 298K CALULATE EA

B) THE FOLLWING DATA WERE OBTAINED DURING THE 1ST ORDER THERMAL

DECOMPOSISTION OF SO2CL2 AT ACONSTANT VOL.

SOCL2(G) -- SO2(G) +CL2(G)

EXE. TIME/S-1 TOTAL PRESSURE / ATM

1. 0 0.5

2. 100 0.6

CALCULAT THE RATE OF REACTION TOTAL PRESSURE IS 0.65 ATM

C) SHOW THAT IN CASE OF FIRST ORDER REACTION ,THE TIME TAKEN FOR COMPLECTION OF 99.9% REACTION IS TEN TIME THE TIME REQUIRED FOR HALF CHANGE OF THE REACTION








D) A FIRST ORDER REACTION IS FOUND TO HAVE A RATE CONSTT.

K=5.5×10-14 S-1. FIND HALF LIFE PERIOD OF THE REACTION

E) DEFFERENSATE BET. ORDER AND MOLECULARITY


A) DRAW EXPRESSION FOR HALF LIFE OF A REACTION OF ZERO ORDER ?

B) DEFINE PSEUDO ORDER REACTION WITH EXAMPAL ?

C) DEFINE : A) ACTIVATION ENERGY B) REACTION RATE

D) IDENTIFY THE REACTION ORDER FROM EACH OF THE FOLL. RATE

CONST. A) K=3×10-4 SEC-1

B) K= 2.3×10-5 L MOL-1SEC-1

Q.19 PREDICT IF THE REACTION BETWEEN THE FOLLOWING IS FEASIBAL

1. AG(S) & FE3+ Eº½AG +/AG = 0.80V Eº½BR2/BR- = 1.09V

2. FE3+(AQ) & BR-(AQ) Eº½FE-/FE2+ = 0.77V

Q.20 THE MOLAR CONDUCTIVITIES AT INFINITE DILUTION FOR SODIUM

ACETATE HCL & NACL ARE 91.0, 425.44 126.45 CM2 MOL-1

RESPECTIVELY AT 298K CAL. MOLAR CONDUCTIVITY OF ACETIC ACID AT INFINITE DELUCTION

Q.21 IF Eº FOR CPPPER ELECTROD IS +0.34V, HOW WILL BE YOU

CALCULATE E.M.F VALUE WHEN THE SOL. IN CONTACT WITH ITS

O.1.M IN COPPER ION HOW DOES E.M.F FOR COPPER ELECTROD

CHANGE WHEN CONC. OF CU2+ ION IN THE SOL.IS DECREASES.








Q.22 WHAT ARE FUEL CELLS DISCUSS H2-O2 FUEL CELL LIST TWO

ADVANTAGE OF FUEL CELLS OVER OTHER CELLS

Q.23 PREDICT THE PRODUCT OF ELECTROLYSIS OBTAINED AT THE

ELECTRODES IN CASE WHEN ELECTROD USED ARE OF PT

A) AN AQUEOUS SOL. OF AgNO3

B) AN AQUEOUS SOL. OF H2SO4

Q.24 HOW DOES THE MOLAR CONDUCTIVITY VARY WITH CONC. FOR

A) WEAK ELECTROLYTE B) STRONG ELECTROLYTE

Q.25 WRITE CELL REACTION WHICH ACCURS IN LEAD STRONGE BATTERY

A) WHEN BATTERY IS IN USE B) WHEN BATTERY IS ON CHARGING

Q.26 STATE HENRY’S LAW & MENTION TWO IMP.APPLICATION

Q.27 WHAT IS MEANT BY +VE & -VE DEVIATION FROM RAOULT’S LAW &

& HOW IS THE SING OF DELTA MIX RELATED TO +VE & -VE DEVIATION FROM RAOULTSS LAW

Q.28 DEF: A) MOLE FRACTION B) MOLALITY C) MOLARITY

Q.29 45G OF ENTHYULENE GLYCOL (C2H6O2) IS MIXED WITH 600G OF WATER

CAL. A) THE FREEZING PT. DEPRESION

B) FREEZING POINT OF SOLUTION ( Given Kf= 1.86 KKgMOL)

Q.30 STATE THE CONDITION RESULTING IN REVERSE OSMOSIS ?

Q.31 WHAT MAKES A GLASS DIFFERENT FREM A SOLID SUCH AS QUARTZ

UNDER WHAT CONDITION COULD QUARTZ BE CONVERTED INTO

GLASS.

Q.32 FOR DETERMINING MOLAR MASS OF MACROMOLECULAR SUBSTANCE IN SOL; THE OSMOTIC PRESSURE MEASURMENT METHOD IS PREFERRED OVER MEASURMENT METHOD OF ANY OTHER COLLAGATIVE OF SOL. GIVE TWO REASONS FOR IT.

Q.33 WHAT WOULD BE THE VALUE OF VAN’T HOFF FACTORS FOR DILUTE SOLUTION OF K2SO4 IN WATER -------------------------------------------------------------------------------------------------------








Q.34 ASSING REASON FOR THE FOLLOWING

I) PHOSPHORUS DOPED SILICON IS A SEMICONDUCTOR

II) SCHOTTKY DEFECT LOWER THE DENSITY OF SOLID

Q.35 DEFINE F- CENTRE

Q36 WHAT IS DOPING?

Q37 A METAL ATOMIC NO. 50 HAS A BODY CENTERED CUBIC CRISTAL. THE DENSITY OF METAL IS 5.96 GCM-3 FIND VOLUME OF UNIT CELL?

Q38 WHY GLASS IS CONSIDERED AS SUPERCOOLED LIQUID?

Q39 WHAT TYPE OF STOICHIOMETRIC DEFECT IS SHOWN BY THE

I) ZnS II) AgBr Q40 WHAT MAKES A GLASS DIFFERENT FROM A SOLIDE SUCH AS QUARTZ? UNDER WHAT CONDITION COULD

QUARTZ BE CONVERTED INTO GLASS.

Q41 ANYSISIS SHOW THAT METAL OXIDE HAS EMPERICAL FORMULA M0.96 O1.00. CALULATE THE PERCENTAGE OF M2+ AND M3+ ION IN THIS CRYSTALS.

Q42 WRITE DIFFERENCE BETWEEN HEXAGONAL CLOSED PACKING AND CUBIC CLOSED PACKING

Q43 DEFINE VANT HOFF FACTOR.? WHAT IS ITS VALUE FOR NON ELECTROLYTIC SOLUTION.

Q44 HOW WILL YOU DETERMINE THE MOLECULAR MASS OF SUBSTANCE FROM OSMOTIC PRESSURE?


Subject – Chemistry

Time Allowed : 3 Hrs. Maximum Marks : 70

General Instructions :

1. All questions are compulsory.








2. Question Nos. 1 to 8 are very short answer questions and carry 1 mark each.3. Question Nos. 9 to 18 are short answer questions and carry 2 mark each.4. Question Nos. 19 to 27 are short answer questions and carry 3 mark each.5. Question Nos. 28 to 30 are long answer questions and carry 5 mark each.6. Use log tables if necessary, use of calculators is not allowed.

Q1) How many effective sodium ions are located at the centres of the faces of a unit cell in sodium chloride crystal?

Q2) What do you observe when Red Blood corpuscles are placed in (i) 1% NaCl Solution, (ii) 0.5% NaCl Solution?

Q3) Give reason for the “blue colour of the sky”.

Q4) Give the role cryolite in the metallurgy of aluminium.

Q5) Write I.U.P.A.C. name for,

Q6) Name the monomer from which Nylon – 6 is manufactured.

Q7) What is Zwitter – ion?

Q8) Complete the following; CH3 – CH2 – NH2 HNO2








Q9) Distinguish between:

(i) Hexagonal Close packing and cubic close packing.(ii) Tetrahedral void and Octahedral void.

Q10) Niobium crystallizes in body centred cubic structure. If density is 8.55 gcm-3, calculate atomic radius of niobium using its atomic mass 93U.

Q11) 45g of ethylene glycol (C2H6O2) is mixed with 600gm of water. Calculate (a) the freezing point depression and (b) the freezing point of the solution.

Q12) The standard electrode potential for Danial Cell is 1.1V. Calculate the Standard Gibbs energy for the reaction : ∆rGo = - RT lnK

Q13) Why do the transition elements exhibit higher enthalpies of atomization?

Q14) [NiCl4]2- is paramagnetic while [Ni(CO)4] is diamagnetic though both are tetrahedral. Why?

Q15) What happens when :

(i) Ethyl chloride is treated with aqueous KOH?(ii)Chlorobenzene is subjected to hydrolysis.

Q16) Explain why :1. The dipole moment of chloroform is lower than that of cyclohexyl chloride?2. Grignard reagents should be prepared under anhydrous conditions?

Q17) Explain the difference between Buna – N and Buna – S.

Q18) Define thermoplastics and thermosetting polymers with two examples of each.

Q19) What are food preservatives? Give one examples.








Q20) Calculate the mole fraction of ethylene glycol (C2H6O2) in a solution containing 20% of C2H6O2 by mass.

Q21) Depict the galvanic cell in which the reaction, Zn(s) + 2Ag+(aq) Zn2+(aq) + 2Ag(s) takes place.(i) Which of the electrode is negatively charged?(ii) The carriers of the current in the cell.(iii) Individual reaction of each electrode.

Q22) Distinguish between physisorption and chemisorptions.

Q23) Why is the extraction of copper from pyrites more difficult than that from its oxide are through reduction?

Q24) What happens when :(i) Concentrated H2SO4 is added to calcium floride?(ii) SO3 is passed through water?

Q25) Write balanced equation for the following:(i) NaCl is heated with sulphuric acid in the presence of MnO2.(ii) Chlorine gas is passed into a solution of NaI in water.

Q26) Write the equation involved in the followed reactions :

(i) Reimer – Tiemann Reaction.(ii) Kolbe’s Reaction(iii) Williamson ether synthesis.

Q27) Give the structure of A, B and C in the following reaction :(i) CH3CH2I NaCN A OH- B NaNO2 + Br2 C

Partial hydrolysis

(ii) CH3COOH NH2 A NaOBr B NaNO2/HCl C ∆

(iii) C6H5NO2 Fe/NHCl A HNO2 B C6H5OH C 273K

Q28) (a) Deduce the structure of XeF4 and XeO3 by applying VSEPR theory. (b) Arrange the following in the order of property indicated.

(i) HOCl, HOClO, HOClO2, HOClO3 (decreasing acid strength)(ii) NH3, PH3, ASH3, SbH3 (decreasing basic strength)(iii) M – F, M – Cl, M – Br, M – I (decreasing ionic character)








OR(a) Write balanced equation for the following :

1) NaClO3 is treated with SO2.2) Ca3P2 is treated with water.

(b) Give reason :(i) CO2 is gas while SiO2 is solid.(ii) SbCl5 is more covalent than SbCl3.(iii) Interhalogen compounds are more reactive than pure halogen.

Q29) Account for the following :

(a) Eo for Mn3+/Mn2+ couple is more positive than for Fe3+/Fe+.(b) Zn2+ salts are white while Cu2+ salts are coloured.(c) Ce3+ can easily oxidized to Ce4+.(d) Zr and Hf exhibit almost similar properties.(e) Transition elements show variable oxidation states.

OR(a) Give the chemical equation involved in the reparation of potassium dichromate from chromite

ore.(b) Write down the effect of PH on K2Cr2O7.(c) Define lanthanoid contraction.

Q30) Calculate the EMF of the cell at 25oC(a) Ni/Ni2+ (0.1M) // Cu2+ (0.1M) / Cu

EoNi2+/Ni = - 0.25 VEoCu2+ / Cu = 0.34 V

(b) How many hours does it take to reduce 3 mole of Fe3+ to Fe2+ with 2 Ampere current 1F = 96500 e-

ORConductivity of 0.00241 M acetic acid is 7.896 × 10-5 SCm-1. Calculate Molal conductivity if m for CH3COOH is 390.55 cm2mol-1. What is dissociation constant?


Subject - Chemistry (Theory)

TIME : 3 Hours M.M. 70

General instructions :-

1. All questions are compulsory -------------------------------------------------------------------------------------------------------








2. Internal choices has been provided in some questions you have to attempt only one of the choice in such questions.

3. Q.No 1 to 8 are very short answer type questions, carrying one mark each.4. Q. No. 9 to 18 are short answer type questions, carrying two mark each.5. Q.No. 19 to 27 are also short answer questions, carrying three mark each.6. Q.No. 28 to 30 are long answer type questions, carrying five mark each.7. Use of calculators is not permitted. However you may use log tables, if necessary.

Q.1 What is an azeotrope?

Q.2 People living at high altitude generally suffer from anoxia , Explain.

Q.3 Define limiting molar conductivity .

Q.4 “A greater insight in to the energetic and mechanistic aspects of reactions”. Explain the above statement which was given by “Max Trautz” and William Lewis”

Q.5 Define the term mutarotation

Q.6 Name one Biodegradable aliphatic polyester.

Q.7 Ortho-sulphobenzimide is used in the preparation of sweet for a diabetic person or patient, why ?

Q.8 How does prevailing temperature influence the extent of adsorption of a gas on solid.

Q.9 What do you mean by activity and selectivity of catalysts?

Q.10 What are the units of molar conductivity?

Q.11 Mention the factors which affect the rate of a chemical reaction.

Q.12 How will you convert –1. Toluene to benzyl alcohol 2. But –1-ene to But -2-ene.

Q.13 Give IUPAC names of following

OCH2 COOH

[1] [2] CI3 – C – CH2 Cl

O

Q.14 Halo arenes are less reactive towards electrophile than benzene.



II

-Cl






OR

Halo alkanes have higher boiling point than the corresponding parent alkane.

.15 Give IUPAC names of following.

a. o- BrC6H4 CH( CH3) CH2 CH3 b. m - Cl C6H4 CH2C (CH3)3








Q.16 How do you explain amphoteric behaviour of amino acids?

Q.17 Define thermoplastic and thermosetting plastic (polymers) with two examples of each.

Q.18 How do antiseptics differ from disinfectants? Give one example of each.

Q.19 What are biodegradable and non-biodegradable detergents? Give one example of each.

1. Q.20 How are peptides formed. Show the formation of a peptide bond with the help of a diagram.

OR

Write short note on- 1. Glycosidic linkage 2. Invert sugar 3. Anomers

Q.21 How will you bring about the following conversions –

[1] Aniline a) Chloro benzene [2] 2-Chloro butane to 3,4- dimethylhexane [3] 1-Bromo propane to 2-Bromo propane

Q.22 [1] Alcohols are comparatively more soluble in water than Hydrocarbons of comparable molecular masses, explain.

[2] Write the reactions of WILLIAMSONS Synthesis of 2-Ethoxy 3-Methyl pentane starting from ethanol and 3- methyl pentan-2-Ol.

Q.23 The density of an atom is 7.2g cm–3. It has bcc structure. The edge length is 288pm. How many atoms of element does 208g of element has?

Q.24 Define Osmotic Pressure. Arrange the following in increasing order of OP:

1. 34.2 g/L of sucrose (M M = 342) 2. 60 g/L Urea (MM = 60) 3. 90 g/L glucose (MM = 180)

Q.25 Calculate standard free energy change for the following chemical reaction –

Q.26 Explain following –

1. Activation Energy 2. Threshold Energy 3. Activated complex.

Q.27 "Action of soap is due to emulsification and micelle formation".Comment.

Q.28 What are the Colligative properties? Explain any one of them. Show that elevation in boiling point is a Colligative property. OR

The following results have been obtained during the kinetic studies of the reaction-

Experiment [A] Mol L-1 [B] Mol L-1 Rate [ mole L-1 min-1]








I 01 01 6.0 x 10-3 mol L-1 min-1

II 0.3 0.2 7.2 x 10-2 mol L-1 min-1

III 0.3 0.4 2.88 x10-1 mol L-1 min-1

IV 0.4 0.1 2.4 x 10-2 mol L-1 min-1

Determine the rate law and the rate constant for the reaction.

Q.29 [a] Write mechanism of acid dehydration of ethanol to yield ethene.

[b] Explain – 1. KOLBE REACTION 2. REIEMER – TIEMANN RACTION.

OR

Explain – 1. Swarts reaction. 2. Diazotisation reaction 3. Zaitsev rule. 4. Sand Meyer reaction

5. Friediel craft’s acylation reaction of chloro benzene

Q.30 a. What is the difference between Reducing and non-reducing sugars or carbohydrates?

b. Differentiate between globular and fibrous proteins.

c. What are Enzymes ?OR

Define –

1. Chemotheraphy 2. Antacids 3. Food preservatives 4. Broad spectrum antibiotics .5 Drug Target.







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