Jamb Chemistry Past Questions For Year 1978
Question 21
If 30cm3 of oxygen diffuses through a porous pot in 7 seconds, how long will it take 60cm3 of chlorine to diffuse through the same pot, if the vapour densities of oxygen and chlorine are 16 and 36 respectively?
- A. 9.3 sec
- B. 14 sec
- C. 21 sec
- D. 28 sec
- E. 30.3 sec
Question 22
The IUPAC names of the compounds CH3COOH and CH2=CH2 are respectively;
- A. acetic acid and ethene
- B. methanoic acid and ethene
- C. methanoic acid and ethylene
- D. ethanol and ethene
- E. acetic acid and ethylene
Question 23
The reaction between an organic acid and an alcohol in the presence of an acid catalyst is known as;
- A. saponification
- B. dehydration
- C. esterification
- D. hydrolysis
- E. hydration
Question 24
During the electrolysis of copper II sulphate between platinum electrodes, if litmus solution is added to the anode compartment,
- A. the litmus turns blue but no gas is evolved
- B. the litmus turns blue and oxygen is evolved
- C. the litmus turns blue and hydrogen is evolved
- D. the litmus turns red and oxygen is evolved
- E. the litmus turns red and then becomes colourless
Question 25
A sample of hard water contains some calcium sulphate and calcium hydrogen carbonate. The total hardness may therefore be removed by
- A. boiling the water
- B. adding excess calcium hydroxide
- C. adding a calculated amount of calcium hydroxide
- D. adding sodium carbonate
- E. adding magnesium hydroxide
