Waec Chemistry 2015 Past Questions and Answers

Question 26:

• WAEC 2015

Which of the following gases will diffuse most rapidly?
[H = 1.00, C = 12.0, O = 16.0, S = 32.0, Cl = 35.5]

A. Cl₂
B. SO₂
C. CH₄
D. C₂H₆

Question 27:

• WAEC 2015

When a reaction is endothermic,

A. Enthalpy change, \(\Delta\)H is negative
B. Heat content of a product is less than the heat content of a reactant
C. Heat content of reactants is less than the heat content of product
D. The reaction is non-spontaneous

Question 28:

• WAEC 2015

Which of the following statements about intermolecular distances and cohesive forces between gas is correct? They are

A. Both large
B. Both negligible
C. Constant and negligible
D. Large and negligible

Question 29:

• WAEC 2015

The following diagram illustrates the rate curve that was obtained when Mg reacted with excess dilute HCl.
The diagram became horizontal at X because

A. The reaction was slowed down
B. All the dilute HCl has reacted
C. All the Mg has reacted
D. Hydrogen gas is produced at a steady rate

Question 30:

• WAEC 2015

An example of an acid salt is

A. CH₃COOONa
B. Mg(OH)Cl
C. NaHSO₄
D. (NH₄)₂SO₄