Chemistry 1991 Jamb Past Questions and Answers

Question 16 :

• JAMB 1991

Which of the following ions is a pollutant in drinking water even in trace amounts?

A. Ca²⁺
B. Hg²⁺
C. Mg²⁺
D. Fe²⁺

Question 17 :

• JAMB 1991

The solubility of copper (II) tetraoxosulphate (Iv) is 75g in 100g of water at 100°C and 25g in 100g of water at 30°C. What mass of the salt would crystallize, if 50g of copper (II) tetraoxosulphate (VI) solution saturated at 100°C were cooled to 30°C ?

A. 57.5
B. 42.2
C. 28.6
D. 14.3

Question 18 :

• JAMB 1991

A sample of temporary hard water can be prepared in the laboratory by?

A. Disolving calcium chloride in distilled water
B. Saturating lime water with carbon (IV) oxide
C. Saturating distilled water with calcium hydroxide
D. Dissolving sodium hydrogen trioxocarbonate (IV) in some distilled water

Question 19 :

• JAMB 1991

A property of a colloidal dispersion which a solution does not have is?

A. The Tyndall effect
B. Homogeneity
C. Osmotic pressure
D. Surface polarity

Question 20 :

• JAMB 1991

50 cm³ of sulphur (IV) oxide, 800 cm³ of ammonia, 450 cm³ of hydrogen chloride, 1.0 cm³ of at 15°C. Which of the following is suitable for demonstrating the fountain experiment?

A. Sulphur (IV) oxide hydrogen chloride
B. Carbon (IV) oxide and amonia
C. Amonia and hydrogen chloride
D. Carbon (IV) oxide and surphur (IV) oxide