Year :
1998
Title :
Chemistry
Exam :
WASSCE/WAEC MAY/JUNE
Paper 1 | Objectives
1 - 10 of 26 Questions
| # | Question | Ans |
|---|---|---|
| 1. |
AN AQUEOUS SOLUTION IS ACIDIC IF A. its pH value is high B. it s corrosive C. it changes the colour of litmus D. it has a bitter taste E. it contains more H3O- than OH- |
E |
| 2. |
The following oxides react with water except A. Na2O B. SO3 C. NO2 D. CO2 E. CuO |
E |
| 3. |
Which of the following is not a property of trioxonitrate (V) salts? A. Positive reaction to the brown ring test B. Ability to dissolve in cold water C. Decomposition on being strongly heated D. Production of effervescence with saturated Na2CO3 solution E. Evolution of gas with concentrated H2SO4 and copper turnings |
D |
| 4. |
Which of the following methods is suitable for the preparation of an insoluble salt? A. Action of an acid on a metal B. Double decomposition C. Neutralisation D. Action of an acid on a trioxocarbonate (IV) E. Action of an acid on an oxide |
B |
| 5. |
What is the function of sulphur (IV) oxide in the reaction represented by the following equation? SO 2(aq) + 2H2S(g) → 3S (s) + 2H 2O (l) A. Dehydrating agent B. Oxidising agent C. Bleaching agent D. Acid E. Precipitant |
B |
| 6. |
Which of the following will produce oxygen and hydrogen during its electrolysis using platinum electrode? A. Glucose solution B. Aqueous copper (ll) tetraoxosulphate (IV) C. Dilute sodium chloride solution D. Concentrated hydrochloric acid E. Dilute copper (ll) chloride solution |
C |
| 7. |
What mass of copper would be deposited by a current of 1. 0 ampere passing for 965 seconds through copper (ll) tetraoxosulphate (IV) solution? [Cu = 63.5; 1F = 96500C] A. 0.318g B. 0.635g C. 18g D. 6.35g E. 9.65g Detailed SolutionCu2+ + 2e- → Cu, From the equation 2 Faraday will liberate 63.5gm of copper The quantity of electricity passed (Q) Q = 1. 0 965 = 965 coulomb :. 2 x 96500 → 63.5, 965 → x. x = 965 / 2x96500 x 63.5 = 0.3175g \(\approx\) 0.328 |
|
| 8. |
How many electrons are removed from Cr2- when it is oxidized to CrO42-? A. o B. 2 C. 4 D. 8 E. 10 |
C |
| 9. |
Substances which absorb water from the atmosphere without dissolving in it are sid to be A. anhydrous B. hygroscopic C. insolube D. hydrated E. efflorescent |
B |
| 10. |
Pipe-borne water is usually chlorinated in order to A. improve the teste of the water B. remove the hardness in the water clear C. coagulate sediments in the water D. kill harmful bacteria in the water E. make the water clear and colourless |
D |
| 1. |
AN AQUEOUS SOLUTION IS ACIDIC IF A. its pH value is high B. it s corrosive C. it changes the colour of litmus D. it has a bitter taste E. it contains more H3O- than OH- |
E |
| 2. |
The following oxides react with water except A. Na2O B. SO3 C. NO2 D. CO2 E. CuO |
E |
| 3. |
Which of the following is not a property of trioxonitrate (V) salts? A. Positive reaction to the brown ring test B. Ability to dissolve in cold water C. Decomposition on being strongly heated D. Production of effervescence with saturated Na2CO3 solution E. Evolution of gas with concentrated H2SO4 and copper turnings |
D |
| 4. |
Which of the following methods is suitable for the preparation of an insoluble salt? A. Action of an acid on a metal B. Double decomposition C. Neutralisation D. Action of an acid on a trioxocarbonate (IV) E. Action of an acid on an oxide |
B |
| 5. |
What is the function of sulphur (IV) oxide in the reaction represented by the following equation? SO 2(aq) + 2H2S(g) → 3S (s) + 2H 2O (l) A. Dehydrating agent B. Oxidising agent C. Bleaching agent D. Acid E. Precipitant |
B |
| 6. |
Which of the following will produce oxygen and hydrogen during its electrolysis using platinum electrode? A. Glucose solution B. Aqueous copper (ll) tetraoxosulphate (IV) C. Dilute sodium chloride solution D. Concentrated hydrochloric acid E. Dilute copper (ll) chloride solution |
C |
| 7. |
What mass of copper would be deposited by a current of 1. 0 ampere passing for 965 seconds through copper (ll) tetraoxosulphate (IV) solution? [Cu = 63.5; 1F = 96500C] A. 0.318g B. 0.635g C. 18g D. 6.35g E. 9.65g Detailed SolutionCu2+ + 2e- → Cu, From the equation 2 Faraday will liberate 63.5gm of copper The quantity of electricity passed (Q) Q = 1. 0 965 = 965 coulomb :. 2 x 96500 → 63.5, 965 → x. x = 965 / 2x96500 x 63.5 = 0.3175g \(\approx\) 0.328 |
|
| 8. |
How many electrons are removed from Cr2- when it is oxidized to CrO42-? A. o B. 2 C. 4 D. 8 E. 10 |
C |
| 9. |
Substances which absorb water from the atmosphere without dissolving in it are sid to be A. anhydrous B. hygroscopic C. insolube D. hydrated E. efflorescent |
B |
| 10. |
Pipe-borne water is usually chlorinated in order to A. improve the teste of the water B. remove the hardness in the water clear C. coagulate sediments in the water D. kill harmful bacteria in the water E. make the water clear and colourless |
D |