1. Skema sbp paper 2 essay part c no. 9, 10

2. Essay part c)
By using suitable examples, state 2 applications of neutralization in daily life [ 4 marks]

3. Use ammonia to prevent latex from coagulate
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
4. Use antacid /sodium hydrogen carbonate to neutralise acid in stomach of gastric patients

4. Any 2 applications ( 4 marks)
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)

5. b) By using one named example for each alkali, explain why the pH values of the alkalis are different ( 6 marks)

6. NOTES on pH values and conc of H + ions and OH - ion
lower
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
lower
higher
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
higher

7. 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

8. Barium carbonate is insoluble salt
Solution X and solution Y are used to prepare barium carbonate salt describe the preparation of barium carbonate salt in the laboratory [ 10 marks]
Barium carbonate is insoluble salt

9. NOTES – soluble and insoluble salts
sulphates
Chlorides
carbonates
nitrates
PCB,
PbSO4, CaSO4, BaSO4
All except
PAH,
PbCl2, AgCl, HgCl2
All except
KAN, K2CO3, Na2CO3, (NH4)2CO3
All except
All

10. Notes on methods to prepare salts
Soluble salts
Not KAN salts
KAN salts
Hot acid + excess solid ( metal/metal oxide/metal hydroxide/metal carbonates) method
Titration method
Insoluble salts
Precipitation or double decomposition

11. State which method to use for the preparation of these salts
notes
State which method to use for the preparation of these salts
Copper(II) sulphate
Barium sulphate
Hot acid + excess
( copper oxide/ copper(II) hydroxide/ copper(II) carbonate
Precipitation
Sodium nitrate
Titration
Silver chloride
Zinc chloride
Precipitation
Hot acid + excess ( zinc/
zinc oxide/ zinc hydroxide/ zinc carbonate
Potassium sulphate
Titration

12. notes TO PREPARE SALT SOLUBLE SALT INSOLUBLE SALT KAN SALTS
NOT KAN SALTS

13. solution 1 is barium nitrate solution 50 cm3 of 1
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 -3
Pour 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

14. Ba(NO3) 2 + Na2CO3  BaCO3 + 2NaNO3
Equation
Ba(NO3) 2 + Na2CO3  BaCO3 + 2NaNO3

15. 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 comp A
= 6C/ C6H14
=12x6/ 6(12) + 14(1) = 72/86
= 84%
% of C in compound B is more than in compound A

16. NOTES Physical properties of organic compound
Ethane or Ethene
Colourless gas ,
low mp and bp,
NOT dissolve in water,
NOT conduct electricity

17. NOTES Physical properties of organic compound
Ethanol
Colourless liquid
Volatile liquid
low mp and bp,
Miscible in water,
NOT conduct electricity

18. Physical properties of organic compound
NOTES
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

19. Physical properties of organic compound
NOTES
Physical properties of organic compound
Colourless liquid,
Sweet smelling
low mp and bp,
volatile liquid,
NOT dissolve in water,
NOT conduct electricity
Floats on water
Less dense than water
Ethyl ethanoate

20. Low melting point and boiling point Does not conduct electricity
b) State one physical property of compound K. Describe briefly a chemical test to differentiate between compound J and compound K [ 6 marks]
Compound K is ethanol
Miscible in water
Low melting point and boiling point
Does not conduct electricity
Volatile colourless liquid

21. Easy chemical test for carbon compounds
notes
Add bromine water,
brown bromine colour decolourise
Alkene
Alcohol
Carboxylic
acid
Add acidified K2Cr2O7 and warm
Orange colour change to green
Add in a few marble chips,
pass the gas through lime water, turns milky

22. J is ethanoic acid K is ethanol
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 acid
K is ethanol

23. 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]

24. 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

25. 1) complete sbp – paper 3 – all questions for tomorrow at 10 pagi
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