Waec Chemistry 2012 Past Questions and Answers

Question 26:

• WAEC 2012

The postulate that molecules are in constant random motion best explains why liquids

A. Can undergo solidification
B. Maintain their volumes
C. Are incompressible
D. Have no characteristic shape

Question 27:

• WAEC 2012

Which of the following gases has the lowest rate of diffusion under the same condition? [H = 1.00; He = 4. 00; O = 16.0; CI = 35.5]

A. CI₂
B. H₂
C. He
D. O₂

Question 28:

• WAEC 2012

The energy evolved when magnesium burns in air is in the form of

A. Heat
B. Heat and sound
C. Light and heat
D. Sound

Question 29:

• WAEC 2012

A substance L reacts with NH\(_4\)NO\(_{3(aq)}\) to generate ammonia gas. L is likely to be

A. HCl
B. NaOH
C. CH₃COOH
D. CaSO₄

Question 30:

• WAEC 2012

On heating, the following trioxocarbonate (IV) salts decompose to give solid residue except

A. Ammonium trioxocarbonate (IV)
B. Calcium trioxocarbonate (IV)
C. Lead (ll) trioxocarbonate(IV)
D. Zinc trioxocarbonate (IV)