Chapter 14, Problem 14.131CP

At 1000 K, K_p, = 2.1 × 10⁶ and $\Delta H°=-\text{1}0\text{7}.\text{7 kJ}$ for the reaction ${\text{H}}_{\text{2}}\left(g\right)+{\text{ Br}}_{\text{2}}\left(g\right)\rightleftharpoons \text{2 HBr}\left(g\right)$ .

(a) A 0.974 mol quantity of Br₂ is added to a 1.00 L reaction vessel that contains 1.22 mol of H₂ gas at 1000 K. What are the partial pressures of H₂, Br₂, and HBr at equilibrium?

(b) For the equilibrium in part (a), each of the following changes will increase the equilibrium partial pressure of HBr. Choose the change that will cause the greatest increase in the pressure of HBr, and explain your choice.

(i) Adding 0.10 mol of H₂

(ii) Adding 0.10 mol of Br₂

(iii) Decreasing the temperature to 700 K.