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

Question 51:

• JAMB 1998

A solid begins to melt when?

A. Constituent particles acquires a greater kinetic energy
B. Energy of vibration of particles of the solid is less than the intermolecular forces
C. Constituent particles acquires energy above the average kinetic energy
D. Energy of vibration of particles of the solid equals the intermolecular forces

Question 52:

• JAMB 1999

In the diagram above, Y is a mixture of

A. Calcium hydroxide and ammonium chloride
B. Calcuim hydroxide and sodium chloride
C. Sodium chloride and ammonuim trioxonitrate (V)
D. Sodium dioxonitrate (lll) and ammouium chloride

Question 53:

• JAMB 1999

In the diagram above, the mixture of the solids P and Q can be separated by

A. Distillation
B. Fractional distillation
C. Crystallization
D. Fractional crystallization

Question 54:

• JAMB 2000

A mixture of iodine and sulphur crystals can be separated by treatment with

A. Water to filter off sulphur
B. Carbon (IV) sulphide to filter off iodine
C. Ethanoic acid to filter off sulphur
D. Methanol to filter off iodine

Question 55:

• JAMB 2000

A mixture of iodine and sulphur crystals can be separated by treatment with

A. Water to filter off sulphur
B. Carbon (IV) sulphide to filter off iodine
C. Ethanoic acid to filter off sulphur
D. Methanol to filter off iodine