Post Utme Chemistry Past Questions and Answers

Question 616:

Oxidation of concentrated hydrochloric acid with manganese (IV) oxide liberates a gas used in the ____________

A. Manufacture of tooth paste
B. Treatment of simple goiter
C. Vulcanization of rubber
D. Sterilization of water

Question 617:

Sodium hydroxide is prepared commercially from sodium chloride solution by ____________

A. Hydrolysis
B. Hydrolysis in steam using a catalyst
C. Electrolysis using iron as anode
D. Treatment of sodium chloride with ammonia and carbon (iv) oxide

Question 618:

An undesirable fraction in the petroleum industry which is particularly prone to knocking is ____________

A. Iso-octane
B. N-heptane
C. Iso-heptane
D. N-octane

Question 619:

Chromatography is used to separate compound of mixtures which differ in their rates of ____________

A. Diffusion
B. Migration
C. Reaction
D. Sedimentation

Question 620:

Which of the following is an example of a chemical change?

A. Dissolution of salt in water
B. Rusting of iron
C. Melting of ice
D. Separating a mixture by distillation