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0. Chapter 15 Chemical Equilibrium. Chemistry, The Central Science , 11th edition Theodore L. Brown; H. Eugene LeMay, Jr.; Bruce E. Bursten and Catherine J. Murphy. Donna Narsavage Heald Siena College Loudonville, NY 2009, Prentice-Hall.
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0 Chapter 15Chemical Equilibrium Chemistry, The Central Science, 11th edition Theodore L. Brown; H. Eugene LeMay, Jr.; Bruce E. Bursten and Catherine J. Murphy Donna Narsavage Heald Siena College Loudonville, NY 2009, Prentice-Hall
P4(s) + 6 Cl2(g) 4 PCl3(l) 0 What is the correct equilibrium constant expression for the reaction:
P4(s) + 6 Cl2(g) 4 PCl3(l) 0 What is the correct equilibrium constant expression for the reaction:
2 NO(g) + O2(g)2 NO2(g) 0 Which accurately reflects the changes in concentration that will occur if O2 is added to disturb the equilibrium?
2 NO(g) + O2(g)2 NO2(g) 0 Which accurately reflects the changes in concentration that will occur if O2 is added to disturb the equilibrium?
PCl3(g) + Cl2(g) PCl5(g) DH° = –87.9 kJ/mol 0 Which of the following will result in an equilibrium shift to the right? • Increase temperature/increase volume • Increase temperature/decrease volume • Decrease temperature/increase volume • Decrease temperature/decrease volume • None of the above PCl5
PCl3(g) + Cl2(g) PCl5(g) DH° = –87.9 kJ/mol 0 Which of the following will result in an equilibrium shift to the right? • Increase temperature/increase volume • Increase temperature/decrease volume • Decrease temperature/increase volume • Decrease temperature/decrease volume • None of the above PCl5
2 CO(g) + O2 (g) 2CO2(g) Kc = 5.0 x 1018 at 25 °C CO2(g) CO(g) + 1/2 O2(g) Kc = ?? at 25 °C 0 What is the value of Kc for the reaction? • Kc= 1/(5.0 x 1018)1/2 • Kc= 1/(2.5 x 1018) • Kc= –(5.0 x 1018)/2 • Kc= –(5.0 x 1018)1/2 • Kc= 2/(5.0 x 1018)1/2
2 CO(g) + O2(g) 2 CO2(g) Kc = 5.0 x 1018 at 25 °C CO2(g) CO(g) + 1/2 O2(g) Kc = ?? at 25 °C 0 What is the value of Kc for the reaction? • Kc= 1/(5.0 x 1018)1/2 • Kc= 1/(2.5 x 1018) • Kc= –(5.0 x 1018)/2 • Kc= –(5.0 x 1018)1/2 • Kc= 2/(5.0 x 1018)1/2
An increase in temperature increases the amount of chlorine present in the following equilibrium. PCl5(s)⇌PCl3(l)+Cl2(g) What is the best explanation for this? A. The higher temperature increases the rate of the forward reaction only. B. The higher temperature increases the rate of the reverse reaction only. C. The higher temperature increases the rate of both reactions but the forward reaction is affected more than the reverse. D. The higher temperature increases the rate of both reactions but the reverse reaction is affected more than the forward.
An increase in temperature increases the amount of chlorine present in the following equilibrium. PCl5(s)⇌PCl3(l)+Cl2(g) What is the best explanation for this? A. The higher temperature increases the rate of the forward reaction only. B. The higher temperature increases the rate of the reverse reaction only. C. The higher temperature increases the rate of both reactions but the forward reaction is affected more than the reverse. D. The higher temperature increases the rate of both reactions but the reverse reaction is affected more than the forward.
What will happen when at a constant temperature, more iodide ions, I−, are added to the equilibrium below? I2(s)+ I-(aq) ⇌ I3-(aq) A. The amount of solid iodine decreases and the equilibrium constant increases. B. The amount of solid iodine decreases and the equilibrium constant remains unchanged. C. The amount of solid iodine increases and the equilibrium constant decreases. D. The amount of solid iodine increases and the equilibrium constant remains unchanged.
What will happen when at a constant temperature, more iodide ions, I−, are added to the equilibrium below? I2(s)+ I-(aq) ⇌ I3-(aq) A. The amount of solid iodine decreases and the equilibrium constant increases. B. The amount of solid iodine decreases and the equilibrium constant remains unchanged. C. The amount of solid iodine increases and the equilibrium constant decreases. D. The amount of solid iodine increases and the equilibrium constant remains unchanged.
Consider the following equilibrium reaction. 2SO2(g)+O2(g) ⇌2SO3(g) ΔHΘ=−197 kJ Which change in conditions will increase the amount of SO3 present when equilibrium is re-established? A. Decreasing the concentration of SO2 B. Increasing the volume C. Decreasing the temperature D. Adding a catalyst
Consider the following equilibrium reaction. 2SO2(g)+O2(g) ⇌2SO3(g) ΔHΘ=−197 kJ Which change in conditions will increase the amount of SO3 present when equilibrium is re-established? A. Decreasing the concentration of SO2 B. Increasing the volume C. Decreasing the temperature D. Adding a catalyst
Consider the following reversible reaction Cr2O72- (aq) +H2O(l) ⇌2CrO42-(aq) +2H+(aq) What will happen to the position of equilibrium and the value of Kc when more H+ ions are added at constant temperature? Position of equilibrium Value of Kc • Shifts to the left decreases • Shifts to the right increases • Shifts to the right does not change • Shifts to the left does not change
Consider the following reversible reaction Cr2O72- (aq) +H2O(l) ⇌2CrO42-(aq) +2H+(aq) What will happen to the position of equilibrium and the value of Kc when more H+ ions are added at constant temperature? Position of equilibrium Value of Kc • Shifts to the left decreases • Shifts to the right increases • Shifts to the right does not change • Shifts to the left does not change
What effect will an increase in temperature have on the Kc value and the position of equilibrium in the following reaction? N2(g)+3H2(g) ⇌2NH3(g)ΔH=−92 kJ Kc equilibrium position • Increases shifts to the right • Decreases shifts to the left • Increases shifts to the left • Decreases shifts to the right
What effect will an increase in temperature have on the Kc value and the position of equilibrium in the following reaction? N2(g)+3H2(g) ⇌2NH3(g)ΔH=−92 kJ Kc equilibrium position • Increases shifts to the right • Decreases shifts to the left • Increases shifts to the left • Decreases shifts to the right
Which statement is always correct for a chemical reaction at equilibrium? A. The rate of the forward reaction equals the rate of the reverse reaction. B. The amounts of reactants and products are equal. C. The concentration of the reactants and products are constantly changing. D. The forward reaction occurs to a greater extent than the reverse reaction.
Which statement is always correct for a chemical reaction at equilibrium? A. The rate of the forward reaction equals the rate of the reverse reaction. B. The amounts of reactants and products are equal. C. The concentration of the reactants and products are constantly changing. D. The forward reaction occurs to a greater extent than the reverse reaction.
Which statement is correct for the equilibrium H2O(l)⇌H2O(g) in a closed system at 100 °C? A. All the H2O(l) molecules have been converted to H2O(g). B. The rate of the forward reaction is greater than the rate of the reverse reaction. C. The rate of the forward reaction is less than the rate of the reverse reaction. D. The pressure remains constant.
Which statement is correct for the equilibrium H2O(l)⇌H2O(g) in a closed system at 100 °C? A. All the H2O(l) molecules have been converted to H2O(g). B. The rate of the forward reaction is greater than the rate of the reverse reaction. C. The rate of the forward reaction is less than the rate of the reverse reaction. D. The pressure remains constant.
When gaseous nitrosyl chloride, NOCl (g), decomposes, the following equilibrium is established: 2NOCl(g) ⇌ 2NO(g) +Cl2(g) 2.0 mol of NOCl(g) were placed in a 1.0 dm3 container and allowed to reach equilibrium. At equilibrium 1.0 mol of NOCl(g) was present. What is the value of Kc? A. 0.50 B. 1.0 C. 1.5 D. 2.0
When gaseous nitrosyl chloride, NOCl (g), decomposes, the following equilibrium is established: 2NOCl(g) ⇌ 2NO(g) +Cl2(g) 2.0 mol of NOCl(g) were placed in a 1.0 dm3 container and allowed to reach equilibrium. At equilibrium 1.0 mol of NOCl(g) was present. What is the value of Kc? A. 0.50 B. 1.0 C. 1.5 D. 2.0