The given reaction is:- CH4(g)+2O2(g)⇌CO2(g)+2H2O(g)
Now, KC=[CH4][O2]2[CO2][H2O]2
Now, H2O is pure liquid, so, [H2O]=1 ⇒KC=[CH4][O2]2[CO2] ∵ΔHr=−170.8KJ/mol is negative, so reaction is exothermic by adding O2(g)
or CH4(g) at equilibrium, by Le Chatelier's principle, the equilibrium shift towards right side.