Jamb Chemistry 1989 Past Questions and Answers

Question 11:

• JAMB 1989

How many valence electrons are contained in the element represented ³¹₁₅P?

A. 3
B. 5
C. 15
D. 31

Question 12:

• JAMB 1989

The gaseous pollutant sulphur (IV)oxide is most likely to be detected in fairly reasonable quantities in the area around a plant for the

A. Extraction of aluminium from bauxite
B. Production of margarine
C. Smelting of copper
D. Production of chlorine from brine

Question 13:

• JAMB 1989

Calcium hydroxide is added in the treatment of town water supply to

A. Kill bacteria in the water
B. Facilitate coagulation of organic particles
C. Facilitate sedimentation
D. Improve the taste of the water

Question 14:

• JAMB 1989

A hydrated salt of formula MSO₄.xH₂ O CONTAINS 45.3% by mass of water of crystalisation. Calculate the value of x [M = 56, S = 32, O = 16, H = 1 ]

A. 3
B. 5
C. 7
D. 10

Question 15:

• JAMB 1989

Using 50 cm ³ of 1 M potassium hydroxide and 100cm ³ of 1 M tetraoxosulphate (VI) acid, calculate the respective volumes in cm ³ of base and acid that would be required to produce the maximum amount of potassium tetraoxosulphate (IV) [ = 39, S = 32, O = 16, H = 1]

A. 50, 50
B. 25, 50
C. 50, 25
D. 25, 25