Higher Chemistry Unit 3 Section 3 Equilibrium Multiple Choice Questions This is designed to be used by teachers to help students develop skills in answering multiple choice questions. Douglas Racey, Waid Academy, Anstruther, Fife, Scotland

Higher Chemistry Unit 3 - Section 3 Equilibrium Multiple Choice Questions 1. A catalyst is added to a reaction at equilibrium. Which of the following does not apply? A.the rate of the forward reaction increases B.the rate of the reverse reaction increases C.the position of equilibrium remains unchanged D.the position of equilibrium shifts to the right Answer D.

2. ICl(l) + Cl 2 (g)  ICl 3 (s)  H= -106 kJmol -1 Which line in the table identifies correctly the changes that will cause the greatest increase in the proportion of solid in the above equilibrium? TemperaturePressure A.DecreaseDecrease B.DecreaseIncrease C.IncreaseDecrease D.IncreaseIncrease Answer B. Higher Chemistry Unit 3 - Section 3 Equilibrium Multiple Choice Questions

3.Which of the following is likely to apply to the use of a catalyst in a chemical reaction? position of  H value equilibrium A.moves to rightdecreases B.unaffectedincreases C.moves to leftunaffected D.unaffectedunaffected Answer D. Higher Chemistry Unit 3 - Section 3 Equilibrium Multiple Choice Questions

4. Cl 2 (g) + H 2 O(l)  Cl – (aq) + ClO - (aq) + 2H + (aq) The addition of which substance would move the above equilibrium to the right? A.hydrogen B.hydrogen chloride C.sodium chloride D.sodium hydroxide Answer D. Higher Chemistry Unit 3 - Section 3 Equilibrium Multiple Choice Questions

5. Chemical reactions are in a state of dynamic equilibrium only when A.the rate of the forward reaction equals that of the backward reaction B.the concentrations of reactants and products are equal C.the activation energies of the forward and backward reactions are equal D.the reaction involves zero enthalpy change Answer A. Higher Chemistry Unit 3 - Section 3 Equilibrium Multiple Choice Questions

6. In which of the following systems will the equilibrium position be unaffected by a change in pressure? A.2NO 2 (g)  N 2 O 4 (g) B.H 2 (g) + I 2 (g)  2HI (g) C.N 2 (g) + 3H 2 (g)  2NH 3 (g) D.2NO(g) + O 2 (g)  2NO 2 (g) Answer B. Higher Chemistry Unit 3 - Section 3 Equilibrium Multiple Choice Questions

7. In a reversible reaction, equilibrium is reached when A.molecules of reactants cease to change into molecules of products B.the concentration of reactants and products are equal C.the concentration of reactants and products are constant D.the activation energies of the forward and reverse reactions are equal Answer C. Higher Chemistry Unit 3 - Section 3 Equilibrium Multiple Choice Questions

8. Ag + (aq) + Fe 2+ (aq)  Ag(s) + Fe 3+ (aq) The addition of which compound would lead to an increase in the mass of silver deposited? The addition of which compound would lead to an increase in the mass of silver deposited? A.Hydrochloric acid B.Iron(II) sulphate C.Iron(III) hydroxide D.Sulphuric acid Answer B. Higher Chemistry Unit 3 - Section 3 Equilibrium Multiple Choice Questions

9. Some solid ammonium chloride is added to a dilute solution of ammonia. solution of ammonia. Which of the following ions will decrease in concentration as a result? Which of the following ions will decrease in concentration as a result? A.Chloride B.Ammonium C.Hydrogen D.Hydroxide Answer D. Higher Chemistry Unit 3 - Section 3 Equilibrium Multiple Choice Questions

10. N 2 O 4 (g)  2NO 2 (g)  H = +57kJ mol -1 Which of the following will increase the concentration of nitrogen dioxide? Which of the following will increase the concentration of nitrogen dioxide? A.Use of a catalyst B.Increase in pressure C.Increase in temperature D.Decrease in temperature Answer C. Higher Chemistry Unit 3 - Section 3 Equilibrium Multiple Choice Questions