Question

What would cause the equilibrium to shift left in this reaction? CO + 3H2 ⇌ CH4 + H2O

Answer 1

if the forward reaction is exothermic then raising the temperature will do the opposite which is an endothermic reaction therefor causing the equilibrium to shift to the left

Answer 2

CO + 3H₂ → CH₄ + H₂O [ΔH = -210 kJmol⁻¹]

The reaction in forward direction is then exothermic.

Thus in backward direction it'd be endothermic,

Thus simply just by raising the temperature of the reaction environment the equilibrium can be shifted to the left.

CH₄ + H₂O → CO + 3H₂ [ΔH = 210 kJmol⁻¹]