Jamb Chemistry Past Questions and Answers

Question 76:

• JAMB 1978

When each of the nitrates of Potassium, Magnesium and iron is heated,

A. All the nitrates decompose to their oxides
B. The nitrate of magnesium gives the nitrite and oxygen
C. The nitrates of iron magnesium and iron give the oxides
D. The nitrate of iron gives the nitrite and oxygen
E. The nitrate of the magnesium is not decomposed

Question 77:

• JAMB 1978

Which of the following metals cannot replace hydrogen from water or steam?

A. Sodium
B. Magnesium
C. Iron
D. Calcium
E. Copper

Question 78:

• JAMB 1978

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

Question 79:

• JAMB 1978

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 80:

• JAMB 1978

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