Question 641:

• 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 642:

• 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 643:

• 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 644:

• 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

Question 645:

• JAMB 1990

A cycloalkane with the molecular formula C₅H₁₀ has ?

A. One isomer
B. Two isomers
C. Three isomers
D. Four isomers