Consider the following system at equilibrium where Delta H degree = 108 kJ, and
ID: 532674 • Letter: C
Question
Consider the following system at equilibrium where Delta H degree = 108 kJ, and K_c = 1.29 times 10^-2, at 600 K: COCl_2 (g) CO (g) + Cl_2 (g) If the TEMPERATURE on the equilibrium system is suddenly increased: The value of K_c A. Increases B. Decreases C. Remains the same The value of Q_c A. Is greater than B. Is equal to K_c C. Is less than K_c The reaction must: A. Run in the forward direction to reestablish equilibrium. B. Run in the reverse direction to reestablish equilibrium. C. Remain the same. Already at equilibrium. The concentration of CI_2 will: A. Increase. B. Decrease. C. Remain the same.Explanation / Answer
For the reaction, Equilibrium constant Kc= [CO] [Cl2]/[COCl2]
This is an endothermic reaction as indicated by +ve enthalpy change
When temperature is increased, as per the lechatlier principle, the reaction proceeds so as to compendate the effect of increase in temperature. This allows the reaction to proceed in the endothermic direction. Hence KC will be increasing.
When QC<Kc,the concentration of the reactants is higher than it would be at equilibrium; the reaction will favor the forward reaction and some of the excess reactant is used to make more product.
Since K is increased as the temperature is increased, the reaction must run in the forward direction to establish the equilibrium and to increase the equilibrium constant.
This leads to more formation of Cl2.