Waec Chemistry 2020 Past Questions and Answers

Question 26:

• WAEC 2020

Which of the following statements is correet for a reaction at equilibrium?

A. All reactions cease to occur
B. The eaction has gone to completion
C. The rates of the forward and backward reactions are equal
D. The amount of product equals the amount of reactants

Question 27:

• WAEC 2020

Which of the following reactions are always exothermic? 1. Neutralization Il. Decomposition III. Combustion

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

Question 28:

• WAEC 2020

Which of the following standard conditions is not correct about energy changes?

A. Standard temperature is 298K
B. B. Standard pressure is 1 atm
C. Concentration of solution must be 1 mol/dm\(^3\)
D. ΔH at 298 K is the activation energy

Question 29:

• WAEC 2020

f 5.0 cm\(^-3\) of 0.200 mol dm(^-3\) Na\(_2\)CO\(_3\) was diluted to 250cm(^-3\) solution, what would be the concentration of the resulting solution?

A. 0.004 mol dm(^-3\)
B. 0.020 mol dm(^-3\)
C. 0.200 mol dm(^-3\)
D. 0.400 mol dm(^-3\)

Question 30:

• WAEC 2020

The initial volume and pressure of a given mass of gas is V and 3.P. What is its pressure if its volume is increased to 2V at constant temperature?

A. 3 P
B. 2P
C. \(frac{3}{2}\) P
D. \(frac{2}{3}\) P