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

Question 76:

• JAMB 2009

A mixture of sugar and sulphur can be separated by

A. Dissolution in water, evapouration and filtration
B. Filtration, evaporation and dissolution in water
C. Dissolution in water, filtration and evaporation
D. Evaporation, dissolution in water and filtration

Question 77:

• JAMB 2009

Which of the following is a physical change?

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

Question 78:

• JAMB 2009

The mixture of gases used in a photographer's flash tube is

A. Argon and krypton
B. Krypton and xenon
C. Helium and argon
D. Argon and xenon

Question 79:

• JAMB 2009

For a given solute, the concentration of its saturated solution in different solvents are

A. The same at the same temperature
B. Different at the same temperature
C. The same at different temperature
D. Constant

Question 80:

• JAMB 2009

The major source of oxides of nitrogen is from the burning of

A. Coal
B. Wood
C. Fuel
D. Chlrofluorocarbons