CHEMISTRY · Multi-part · A Level · Chemistry · Chemical equilibria (Le Chatelier’s principle and Kc) · Chemical equilibria (Le Chatelier’s principle and Kc)
Problem
Consider the two gaseous equilibria shown below.
Reaction I: 2 NO₂(g) ⇌ N₂O₄(g) ΔH∘=−57kJ
Reaction II: H₂(g) + I₂(g) ⇌ 2 HI(g) ΔH∘=+53kJ
(a) When the temperature is raised from 298K to 350K, predict whether K for each reaction increases, decreases, or remains unchanged. Provide a separate justification for each reaction.
(b) For Reaction II, describe how the relative amounts of H₂, I₂, and HI present at equilibrium change (increase, decrease, or remain the same) when the temperature is raised. Explain your reasoning.