Jamb Chemistry Past Questions and Answers

Question 71:

• JAMB 1978

The oxidation state of chlorine in potassium chlorate is

A. +1
B. +2
C. +3
D. +5
E. +7

Question 72:

• JAMB 1978

When air which contains the gases Oxygen, nitrogen, carbondioxide, water vapour and the rare gases, is passed through alkaline pyrogallol and then over quicklime, the only gases left are;

A. Nitrogen and carbondioxide
B. The rare gases
C. Nitrogen and oxygen
D. Nitrogen and the rare gases
E. Nitrogen, carbondioxide and the rare gases

Question 73:

• JAMB 1978

When heat is absorbed during a chemical reaction, the reaction is said to be

A. Thermodynamic
B. Exothermic
C. Isothermal
D. Endothermic
E. Thermostatic

Question 74:

• JAMB 1978

When large hydrocarbon molecules are heated at high temperature in the presence of a catalyst to give smaller molecules, the process is known as

A. Disintegration
B. Polymerization
C. Cracking
D. Degradation
E. Distillation

Question 75:

• JAMB 1978

The pH of four solutions W, X, Y, Z are 4, 6, 8, 10 respectively, therefore

A. None of these solutions is acidic
B. The pH of Y is made more acidic by addition of distilled water
C. Z is the most acidic solution
D. W is the most acidic solution
E. X is neutral