Methanol can be synthesized according to the equilibrium reaction CO(g) + 2 H2(g) ⇌…
CHEMISTRY · Multi-part · A Level · Chemistry · Chemical equilibria (Le Chatelier’s principle and Kc) · Chemical equilibria (Le Chatelier’s principle and Kc)
Problem
Methanol can be synthesized according to the equilibrium reaction
CO(g) + 2 H2(g) ⇌ CH3OH(g)
A rigid 1.0 L reaction vessel at 450 K is depicted with the following particles:
• 6 CO molecules
• 10 H2 molecules
• 1 CH3OH molecule
• 5 He atoms (present as an inert carrier gas)
The equilibrium constant at 450 K is Kc = 0.85.
(a) Calculate the reaction quotient Qc for the reaction mixture at the instant depicted. Clearly indicate how you translated the particle counts into molar concentrations.
(b) Using a comparison between Qc and Kc, predict the direction in which the reaction will shift as equilibrium is approached.
(c) Provide a brief explanation for why the helium atoms do not appear in either the Qc or Kc expressions, even though they are physically present in the vessel.