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

Question 131:

• JAMB 2020

When a solid substance disappears completely as a gas on heating, the substance is said to have undergone?

A. Sublimation
B. Crystallization
C. Distillation
D. Evaporation

Question 132:

• JAMB 2020

To obtain pure carbon(ii)oxide from its mixture with carbon(iv)oxide, the mixture should be?

A. Passed over heated copper(ii)oxide
B. Bubbled through water
C. Bubbled through conc H\(_2\)SO\(_4\)
D. Bubbled through conc NAOH

Question 133:

• JAMB 2021

Which of the following is a form of calcium carbonate?
I. limestone
II. marble
III. chalk
Iv. egg-shells

A. I only
B. I, II and IV
C. I and II only
D. I, II, III, and IV

Question 134:

• JAMB 2021

A sample of any of the following substances disappears after some time when exposed to the air like camphor, naphthalene, or dry ice.

This phenomenon is called?

A. Sublimation
B. Evaporation
C. Diffusion
D. Radiation

Question 135:

• JAMB 2021

Which one of the following is not a mixture?

A. Air
B. Mercury
C. Milk
D. Cement