Jamb Chemistry 1981 Past Questions and Answers

Question 36:

• JAMB 1981

5cm³ of a saturated solution of sodium chloride at 30°C gave, on careful evaporation, 1.95g of solid salt. The solubility of sodium chloride at 30°C?
(Na = 23, Cl = 35.5)

A. 5.00 mole dm³
B. 5.67 mole dm³
C. 6.00 mole dm³
D. 6.67 mole dm³
E. 7.00 mole dm³

Question 37:

• JAMB 1981

In the extraction of iron, which of the following reactions does NOT take place in the blast furnace?

A. CO₂ + C → 2CO
B. 2Fe₂O₃ + 3C → 4Fe + 3CO₂
C. Fe₂O₃ + 3C → 2Fe + 3CO₂
D. CaCO₃ → CaO + CO₂
E. CaO + SiO₂ → CaSiO₃

Question 38:

• JAMB 1981

Pure sulphuric acid is a liquid of 1:84 density. What volume of it would be required to prepare 250 cm³ of 2.0 M solution?
(H = 1, S = 32, O = 16)

A. 2.00
B. 2.66
C. 3.00
D. 3.66
E. 4.00

Question 39:

• JAMB 1981

What mass of sodium carbonate solution is in 500 cm³ of 0.1 molar sodium carbonate solution?
(Na = 23, C = 12, O = 16)

A. 10.6 g
B. 5.3 g
C. 500 g
D. 10 g
E. 20 g

Question 40:

• JAMB 1981

Which of the following compounds and elements would sublime on exposure to the atmosphere?

A. Ice
B. Sulphur
C. Phosphurous
D. Iodine
E. Potassium iodie