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

Question 61:

• JAMB 2002

The chromatography separation of ink is based on the ability of the components to

A. React with solvent
B. React with each other
C. Dissolve in each other in the column
D. Move at different speeds in the column

Question 62:

• JAMB 2003

Which of the following is physical change?

A. Burning kerosene
B. Freezing ice cream
C. Exposing white phosphorus
D. Dissolving calcium in water

Question 63:

• JAMB 2003

The filter in the cigarette reduces the nicotine content by

A. Burning
B. Adsorption
C. Evaporation
D. Absorption

Question 64:

• JAMB 2005

When water boilers are used for long period of time, the solid substances left behind as scale are

A. Magnesium trioxosilicate (IV) and rust
B. Magnesium trioxosilicate (IV) and calcium tetraoxosulphate (VI)
C. Clay and magnesium troxosulphate (IV)
D. Clay and rust

Question 65:

• JAMB 2005

A heterogenous mixture can be defined as any mixture

A. Of a solute nd a solvent
B. Whose cmposition is uniform
C. Whose composition is not uniform
D. Formed by solids and liquids