SKEMA SBP PAPER 2 ESSAY PART C NO. 9, 10. BY USING SUITABLE EXAMPLES, STATE 2 APPLICATIONS OF...
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Transcript of SKEMA SBP PAPER 2 ESSAY PART C NO. 9, 10. BY USING SUITABLE EXAMPLES, STATE 2 APPLICATIONS OF...
SKEMA SBP PAPER 2ESSAY PART C
NO. 9, 10
BY USING SUITABLE EXAMPLES, STATE 2 APPLICATIONS OF
NEUTRALIZATION IN DAILY LIFE [ 4 MARKS]
Essay part c)
1. Use ammonia to prevent latex from coagulate
4. Use antacid /sodium hydrogen carbonate to neutralise acid in stomach of gastric patients
2. Use lime /quick lime (calcium oxide)/ slaked lime (calcium hydroxide), chalk (calcium carbonate) to neutralise acidic soil
3. Use magnesium hydroxide / toothpaste to neutralise acid produced by bacteria in our mouth
•RUB BEE STING OR ANT STINGS ( WHICH IS ACIDIC)WITH CALCIUM CARBONATE
•RUB WASP STING ( WHICH IS ALKALINE ) WITH VINEGAR
Any 2 applications ( 4 marks)
B) BY USING ONE NAMED EXAMPLE FOR EACH ALKALI, EXPLAIN WHY THE PH VALUES OF THE ALKALIS ARE DIFFERENT ( 6 MARKS)
NOTES ON PH VALUES AND CONC OF H + IONS AND OH - ION
•THE HIGHER THE CONC OF H+ ION, THE ……..THE PH VALUE
•SO STRONG ACID HAS A … … PH VALUE THAN A WEAK ACID OF THE SAME CONCENTRATION
•THE HIGHER THE CONC OF OH- ION, THE …..THE PH VALUE
•SO STRONG ALKALI HAS A ……. PH VALUE THAN A WEAK ALKALI OF THE SAME CONCENTRATION
lower
higher
higher
lower
Example of R ; sodium hydroxide solution/ litium hydroxide solution/ potassium hydroxide solution (any strong alkali)R ionised completely in water and produced high concentration of OH- ions
Example of Q : ammonia aqueous / solution ( weak alkali)
Q ionised partially in water and produce low concentration of OH- ions the higher the concentration of OH – ions in R the higher the pH values
SOLUTION X AND SOLUTION Y ARE USED TO PREPARE BARIUM CARBONATE
SALTDESCRIBE THE PREPARATION OF BARIUM CARBONATE SALT IN THE
LABORATORY[ 10 MARKS]
Barium carbonate is insoluble salt
NOTES – SOLUBLE AND INSOLUBLE SALTS
Soluble Insoluble sulphatesChlorides
carbonates
nitrates
All except PCB, PbSO4, CaSO4, BaSO4All except PAH, PbCl2, AgCl, HgCl2
KAN, K2CO3, Na2CO3, (NH4)2CO3
All except
All
NOTES ON METHODS TO PREPARE SALTS
KAN salts
Soluble salts
Not KAN salts
Insoluble salts
Titration methodHot acid + excess solid
( metal/metal oxide/metal
hydroxide/metal carbonates) method
Precipitation or double decomposition
STATE WHICH METHOD TO USE FOR THE PREPARATION OF THESE SALTS
BARIUM SULPHATE Precipitation
Sodium nitrate Titration
Zinc chloride Hot acid + excess ( zinc/
zinc oxide/ zinc hydroxide/ zinc carbonate
Copper(II) sulphate
Silver chloride
Potassium sulphate
Hot acid + excess ( copper oxide/ copper(II)
hydroxide/ copper(II) carbonate
Precipitation
Titration
notes
TO PREPARE SALT
SOLUBLE SALT INSOLUBLE SALT
KAN SALTS NOT KAN SALTS
notes
solution 1 is barium nitrate solution 50 cm3
of 1.0 moldm -3
Soln 2 is sodium carbonate solution 50 cm3
of 1.0 moldm -3Pour solution 1 into a beaker
Add solution 2 into the beaker with solution 1
Stir the mixture using glass rod
Filter the mixture
Rinse the residue with distilled water
Dry the residue in between sheet of filter papers to dry
EQUATION
•Ba(NO3) 2 + Na2CO3 BaCO3 +
2NaNO3
10 A)COMPOUND A AND B BURNT COMPLETELY IN OXYGEN O PRODUCE CARBON DIOXIDE
AND WATER
•A) NAME COMPOUND B
•WHY COMPOUND B PRODUCE MORE SOOT [ 4 MARKS]
1- hexene or hex-1-ene
% of C in compound B = 6C/ C6H12 =12x6/ 6(12) + 12(1) = 72/84= 86%
% of C in compound B is more than in compound A
% of C in comp A = 6C/ C6H14 =12x6/ 6(12) + 14(1) = 72/86= 84%
NOTES PHYSICAL PROPERTIES OF ORGANIC COMPOUND
•ETHANE OR ETHENE• Colourless gas , • low mp and bp, • NOT dissolve in
water, • NOT conduct
electricity
NOTES PHYSICAL PROPERTIES OF ORGANIC COMPOUND
•ETHANOL • Colourless liquid• Volatile liquid• low mp and bp, • Miscible in water, • NOT conduct
electricity
PHYSICAL PROPERTIES OF ORGANIC COMPOUND
•ETHANOIC
ACID
• Colourless liquid• Volatile liquid• low mp and bp, • dissolve in water, • NOT conduct electricity in
glacial form, but conduct electricity in aqueous form
NOTES
PHYSICAL PROPERTIES OF ORGANIC COMPOUND
•ETHYL ETHANOATE • Colourless liquid, • Sweet smelling • low mp and bp, • volatile liquid, • NOT dissolve in
water, • NOT conduct
electricity• Floats on water • Less dense than
water
NOTES
B) STATE ONE PHYSICAL PROPERTY OF COMPOUND K. DESCRIBE BRIEFLY A CHEMICAL TEST TO
DIFFERENTIATE BETWEEN COMPOUND J AND COMPOUND K [ 6 MARKS]
•MISCIBLE IN WATER
•LOW MELTING POINT AND BOILING POINT
•DOES NOT CONDUCT ELECTRICITY
•VOLATILE COLOURLESS LIQUID
•COMPOUND K IS ETHANOL
EASY CHEMICAL TEST FOR CARBON COMPOUNDS
•ALKENE
•ALCOHOL
•CARBOXYLIC
ACID
notesAdd bromine water,
brown bromine colour decolourise
Add acidified K2Cr2O7 and warmOrange colour change to green
Add in a few marble chips, pass the gas through lime water, turns milky
DESCRIBE BRIEFLY A CHEMICAL TEST TO DIFFERENTIATE BETWEEN COMPOUND J AND
COMPOUND K [ 6 MARKS]•Pour 2 cm3 of compound J into a test tube
•Add a few drops of acidified
potassium dichromate(VI) solution
•Warm slowly , Observe colour change
•Repeat the procedure above with compound K
• If acidified potassium dichromate solution change from orange to green, then the compound is alcohol
J is ethanoic acidK is ethanol
DESCRIBE HOW TO PREPARE AN ALKENE FROM A NAMED ALCOHOL THROUGH DEHYDRATION PROCESS. IN YOUR DESCRIPTION,
INCLUDE THE DIAGRAM OF THE APPARATUS SET UP AND BALANCED CHEMICAL EQUATION FOR THE REACTION [ 10 MARKS]
•2. Place glass wool in a boiling tube
•3. Add a few drops of ethanol to the glass wool
•4. Clamp the boiling tube horizontally
•5. Place a porcelain chips in the middle of the boiling tube
•6. Heat the porcelain chips strongly
•7. Heat the ethanol
•8. Collect the gas produced in a test tube
•9. Equation: C2H5OH → C2H4 + H2O
HOMEWORK
•1) COMPLETE SBP – PAPER 3 – ALL QUESTIONS FOR TOMORROW AT 10 PAGI
•2) READ UP PLANNING EXPERIMENT- 6 EXAMPLES WITH ANSWERS
•3) READ UP ESSAY AND ANSWERS MARA SECTION B AND C