Jamb Chemistry 1990 Past Questions and Answers

Question 16:

• JAMB 1990

Coal fire should not be used in poorly ventilated rooms because ?

A. Of the accumulation of CO₂ which causes dep sleep
B. It is usually too hot
C. Of the acumulation of CO which causes suffocation
D. It removes most most of the gases in the rooms

Question 17:

• JAMB 1990

The major component of the slag from the production of iron is?

A. An alloy of calcium and iron
B. Coke
C. Impure iron
D. Calcium trioxosilicate (IV)

Question 18:

• JAMB 1990

Sodium hydrogen should be stored in properly closed containers because it?

A. Readily asborbs water vapour to air
B. Is easily oxidize by atmospheric oxygen
C. Turns golden yellow when exposed to light
D. Melts at a low temperature

Question 19:

• JAMB 1990

To make coloured glasses, small quantities of oxides of metals which form coloured silicates are often added to the reaction mixture consisting of Na₂CO₃ and SiO₂. Such a metals is a?.

A. Pottasium
B. Barium
C. Zinc
D. Copper

Question 20:

• JAMB 1990

Which of the following compounds gives a yellow residue when heated and also reacts with aqueous sodium hydroxide to give a white gelatinous precipitate soluble in excess sodium hydroxide solution?

A. (NH₄)CO₃
B. ZnCO₃
C. Al₂(SO₄)₃
D. PbCO[sub][/sub]3