Separation of mixtures and purification of chemical substances - Jamb Chemistry Past Questions and Answers

Question 106:

• JAMB 2018

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

Question 107:

• JAMB 2018

If 1 litre of 2.2M sulphuric acid is poured into a bucket containing 10 litres of water and the resulting solution mixed thoroughly, the resulting sulphuric acid concentration will be

A. 2.2M
B. 1.1M
C. 0.22M
D. 0.11M

Question 108:

• JAMB 2018

The boiling of fat and aqueous caustic soda is referred to as

A. Hydrolysis
B. Esterification
C. Acidification
D. Saponification

Question 109:

• JAMB 2018

Methanoic acid mixes with water in all proportions and has about the same boiling point as water. Which of the following methods would you adopt to obtain pure water from a mixture of Sand, water and methanoic acid?

A. Fractional distillation
B. Filtration followed by distillation
C. Neutralization with sodium hydroxide followed by distillation
D. Neutralization with sodium hydroxide followed by filtration

Question 110:

• JAMB 2018

Suitable reagents for the laboratory preparation nitrogen are

A. Sodium dioxonitrate(III) and ammonium chloride
B. Sodium trioxonitrate(V) and ammonium chloride
C. Sodium chloride and ammonium trioxonitrate(V)
D. Sodium chloride and ammonium di-ozonitrate(III)