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Equilibrium

Equilibrium. Click to start. The concentrations of the reactants adnd products are equal. A. The forward reaction is exothermic. B. The forward and reverse reactions proceed at equal rates. C. The forward and reverse reactions have stopped. D. Question 1.

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Equilibrium

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  1. Equilibrium Click to start

  2. The concentrations of the reactants adnd products are equal. A The forward reaction is exothermic. B The forward and reverse reactions proceed at equal rates. C The forward and reverse reactions have stopped. D Question 1 Which statement is true about chemical reactions at equilibrium?

  3. Wrong Answer! The equation is dynamic with the rates of forward and reverse reactions equal. Try Again

  4. A I only B II only C I and III only II and III only D Question 2 Which statement(s) is/are true for a mixture of ice and water at equilibrium? • The rates of melting and freezing are equal. • The amounts of ice and water are equal. • The same position of equilibrium can be reached by cooling water or heating ice.

  5. Wrong Answer! I is correct as the equation is dynamic, III is correct as the equilibrium can be reached from either direction. Try Again

  6. A I and II only B I and III only C II and III only I, II and III D Question 3 Which statements are correct for a reaction at equilibrium? • The forward and reverse reactions both continue. • The rates of forward and reverse reactions are equal. • The concentrations of reactants and products are equal.

  7. Wrong Answer! I and II are correct for the equilibrium involved is a dynamic process; III is not necessary true, the balance, that is the position of equilibrium depends on the conditions. Try Again

  8. A An increase in temperature B Adding a catalyst An increase in pressure A decrease in temperature C D Question 4 The following equilibrium can be set up in a closed container. N2O4(g) 2NO2(g) ΔH = +57 kJmol-1 colourless brown Which of the following changes would produce a darkening of the colour of the gaseous mixture in the container?

  9. Wrong Answer! The forward reaction is endothermic and favoured by an increase in temperature, so more NO2 is present in the equilibrium mixture (so the mixture is browner) Try Again

  10. A Shifts towards the products Decreases B Shifts towards the reactants Decreases C Shifts towards the reactants Increases Shifts towards the products Increases D Question 5 What changes occur when the temperature is increased in the following reaction at equilibrium? Br2(g) +Cl2(g) 2BrCl(g) ΔH = +14 kJmol-1 Position of equiibrium Value of equilibrium constant

  11. Wrong Answer! The forward reaction is endothermic, favoured by an increased temperature. So the equilibrium shifts to the right; Kc is a measure of how far to the right an equation lies. Try Again

  12. A The amount of SO2Cl2 will have increased. B The amount of SO2Cl2 will have decreased. The amount of Cl2 will have remained unchanged. C The amount of Cl2 will have decreased. D Question 6 The volume of the reaction vessel containing the following equilibrium mixture SO2Cl2 (g) SO2(g) + Cl2(g) is increased. When the equilibrium is re-established, which of the following will have occured?

  13. Wrong Answer! The pressure is decreased favouring a shift to the products side of the equilibrium as this involves fewer moles of gas, so the amount of SO2Cl2 is decreased. Try Again

  14. A I, II and III B I and II only C II and III only I and III only D Question 7 Which changes will shift the position of the equilibrium to the right in the following reaction? 2CO2(g) 2CO(g) + O2(g) • Adding a catalyst • Dereasing the oxygen concentration • Increasing the volume of the container

  15. Wrong Answer! I is correct as removing oxygen shifts the reaction to the right. III is correct as reduced pressure favours the side of the equation involving fewer moles of gas, in thies case the products side. Try Again

  16. A B C D Question 8 I2(g) +3Cl2(g) 2ICl3(g) What is the equilbrium constant expression for the reaction above?

  17. Wrong Answer! This is correctly constructed expression which fits the equilibrium law. Try Again

  18. The lower the concentration of products at equilibrium. A the slower the reaction rate. B The faster the reactants are converted to products. C the more endothermic the reaction. D Question 9 The smaller an equilibrium constant, Kc,

  19. Wrong Answer! The higher the value of Kc, the greater the value of the numerator (the top figures) in the equilibrium expression, so the greater the concentration(s) of the products. There is no connection between Kc and the rate at which equilibrium is achieved. Try Again

  20. A 4NH3 +5O2 4NO +6H2O B 4NO +6H2O 4NH3 +5O2 8NH3 +10O2 8NO +12H2O 2NO +3H2O 2NH3 + O2 C D Question 10 For the gaseous reaction, the equilibrium constant expression is: Which equation corresponds to this equilibrium expression?

  21. Wrong Answer! This is correctly constructed expression which fits the equilibrium law. Try Again

  22. The rate of the forward reaction increases and the that of the reverse reaction decreases. The rates of both the forward and reverse reactions increase. A B C The yield of SO3 increases. The value of ΔHƟ increases. D Question 11 The key reaction in the manufacture of sulfuric acid can be represented by the equation below. SO2(g) +O2(g) 2SO3(g) ΔH = -197 kJmol-1 What happens when a catalyst is added to an equilibrium mixture from this reaction?

  23. Wrong Answer! A catalyst speeds up both the forward and reverse reactions equally. The composition of the equilibrium mixture remains unchanged. Try Again

  24. A B 2NO2(g) N2O4(g) 2O3(g) 3O2(g) 2NO(g)+Cl2(g) 2NOCl(g) N2(g)+O2(g) 2NO(g) C D Question 12 In which of the following reactions does the position of equilibrium remain unaffected by change in pressure?

  25. Wrong Answer! There are the same number of moles of as on both sides of the equation. Try Again

  26. Congratulations!

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