At 25 °C, dinitrogen tetroxide and nitrogen dioxide are in equilibrium according to…
CHEMISTRY · Single correct · A Level · Chemistry · Chemical equilibria (Le Chatelier’s principle and Kc) · Chemical equilibria (Le Chatelier’s principle and Kc)
Problem
At 25 °C, dinitrogen tetroxide and nitrogen dioxide are in equilibrium according to
N2O4(g) ⇌ 2 NO2(g) ΔH° = +57 kJ.
A sealed flask at this temperature is at equilibrium. The chemist performs the following two operations in the order given:
1. The partial pressure of NO2 is suddenly doubled by injecting additional NO2(g).
2. A heterogeneous catalyst specific to this reaction is introduced while temperature remains at 25 °C.
Which of the following best describes the combined effect of these two operations on the equilibrium constant Kp for the reaction?
(a) Kp increases after operation 1 and is unchanged by operation 2.
(b) Kp decreases after operation 1 and is unchanged by operation 2.
(c) Kp is unchanged by both operations.
(d) Kp is unchanged by operation 1 but increases after operation 2.