General Science IBDP Chemistry 7. Equilibrium SL June 4, 2021 Shveta 0 Comments Equilibrium, ibdp chemistry 1. I2(g) + 3Cl2(g) 2ICl3(g) What is the equilibrium constant expression for the reaction above?Kc = Kc = Kc = Kc = 2. SO2(g) + O2 (g) 2SO3(g) ∆Hο = –200 kJ According to the above information, what temperature and pressure conditions produce the greatest amount of SO3? ABCD3. Which statement(s) is/are true for a mixture of ice and water at equilibrium? I. The rates of melting and freezing are equal. II. The amounts of ice and water are equal. III. The same position of equilibrium can be reached by cooling water and heating iceI only I and III only II only III only 4. What will happen to the position of equilibrium and the value of the equilibrium constant when the temperature is increased in the following reaction? Br2(g) + Cl2(g) 2BrCl(g) ∆H = +14 kJ ABCD5. Which statement concerning a chemical reaction at equilibrium is not correct?The concentrations of reactants and products remain constantEquilibrium can be approached from both directionsThe rate of the forward reaction equals the rate of the reverse reactionAll reaction stops6. In the reaction below N2(g) + 3H2(g) 2NH3(g) ∆H = –92 kJ which of the following changes will increase the amount of ammonia at equilibrium? Increasing the pressure Increasing the temperature III. Adding a catalystI only II only I and II only II and III only 7. In the Haber process for the synthesis of ammonia, what effects does the catalyst have? ABCD8. What will happen if CO2(g) is allowed to escape from the following reaction mixture at equilibrium? CO2(g) + H2O(l) H+(aq) + HCO3–(aq)The pH will decreaseThe pH will increaseThe pH will remain constantThe pH will become zero9. Which statements are correct for a reaction at equilibrium? I. The forward and reverse reactions both continue. II. The rates of the forward and reverse reactions are equal. III. The concentrations of reactants and products are equal.I and II only I and III only II and III only I, II and III 10. The manufacture of sulfur trioxide can be represented by the equation below. 2SO2(g) + O2(g) 2SO3(g) ∆Hο = –197 kJ mol–1 What happens when a catalyst is added to an equilibrium mixture from this reaction?The rate of the forward reaction increases and that of the reverse reaction decreasesThe rates of both forward and reverse reactions increaseThe value of ∆Hο increasesThe yield of sulfur trioxide increases11. Which changes will shift the position of equilibrium to the right in the following reaction? 2CO2(g) 2CO(g) +O2(g) I. adding a catalyst II. decreasing the oxygen concentration III. increasing the volume of the containerI and II only I and III only II and III only I, II and III 12. Which statement is always true for a chemical reaction that has reached equilibrium? The yield of product(s) is greater than 50%The rate of the forward reaction is greater than the rate of the reverse reactionThe amounts of reactants and products do not changeBoth forward and reverse reactions have stopped13. The equation for a reversible reaction used in industry to convert methane to hydrogen is shown below. CH4(g) + H2O(g) CO(g) + 3H2(g) ΔHӨ = +210 kJ Which statement is always correct about this reaction when equilibrium has been reached?The concentrations of methane and carbon monoxide are equalThe rate of the forward reaction is greater than the rate of the reverse reactionThe amount of hydrogen is three times the amount of methaneThe value of ΔHӨ for the reverse reaction is –210 kJ14. The equation for a reaction used in the manufacture of nitric acid is 4NH3(g) + 5O2(g) 4NO(g) + 6H2O(g) ΔHӨ = –900 kJ Which changes occur when the temperature of the reaction is increased? ABCD15. Which changes cause an increase in the equilibrium yield of SO3(g) in this reaction? 2SO2(g) + O2(g) 2SO3(g) ΔHӨ = –196 kJ I. increasing the pressure II. decreasing the temperature III. adding oxygenI and II only I and III only II and III only I, II and III 16. Iron(III) ions react with thiocyanate ions as follows. Fe3+(aq) + CNS–(aq) Fe(CNS)2+(aq) What are the units of the equilibrium constant, Kc, for the reaction? mol dm–3 mol2 dm–6 mol–1 dm3 mol–2 dm617. Consider the following equilibrium reaction in a closed container at 350°C. SO2(g) + Cl2(g) SO2Cl2(g) ΔHӨ = −85 kJ Which statement is correct?Decreasing the temperature will increase the amount of SO2Cl2(g)Increasing the volume of the container will increase the amount of SO2Cl2(g)Increasing the temperature will increase the amount of SO2Cl2(g)Adding a catalyst will increase the amount of SO2Cl2(g)18. Which of the following equilibria would not be affected by pressure changes at constant temperature?4HCl(g) + O2(g) 2H2O(g) + 2Cl2(g) CO(g) + H2O(g) H2(g) + CO2(g) C2H4(g) + H2O(g) C2H5OH(g)PF3Cl2(g) PF3(g) + Cl2(g) 19. Consider the following equilibrium reaction in a closed container at 350°C SO2(g) + Cl2(g) SO2Cl2(g) ΔHӨ = −85 kJ Which statement is correct?Decreasing the temperature will increase the amount of SO2Cl2(g)Increasing the volume of the container will increase the amount of SO2Cl2(g)Increasing the temperature will increase the amount of SO2Cl2(g)Adding a catalyst will increase the amount of SO2Cl2(g)20. What is the equilibrium constant expression, Kc, for the reaction below? N2(g) + 2O2(g) 2NO2(g)Kc = Kc = Kc = Kc = 21. Sulfur dioxide and oxygen react to form sulfur trioxide according to the equilibrium. 2SO2(g) + O2(g) 2SO3(g) How is the amount of SO2 and the value of the equilibrium constant for the reaction affected by an increase in pressure?The amount of SO3 and the value of the equilibrium constant both increaseThe amount of SO3 and the value of the equilibrium constant both decreaseThe amount of SO3 increases but the value of the equilibrium constant decreasesThe amount of SO3 increases but the value of the equilibrium constant does not change22. The equation for the Haber process is: N2(g) + 3H2(g) 2NH3(g) ΔHӨ = −92.2 kJ Which conditions will favour the production of the greatest amount of ammonia at equilibrium?High temperature and high pressure High temperature and low pressureLow temperature and high pressureLow temperature and low pressure23. The sequence of diagrams represents the system as time passes for a gas phase reaction in which reactant X is converted to product Y. Which statement is correct?At t = 5 days the rate of the forward reaction is greater than the rate of the backward reaction At t = 7 seconds the reaction has reached completionAt t = 10 minutes the system has reached a state of equilibriumAt t = 5 days the rate of the forward reaction is less than the rate of the backward reaction24. What changes occur when the temperature is increased in the following reaction at equilibrium? Br2(g) + Cl2(g) 2BrCl(g) ∆Hο = +14 kJ mol–1 ABCD
