## General Chemistry: Principles and Modern Applications (10th Edition)

We need the K value for the following reaction: $$CH_4(g) + H_2O(g) \rightleftharpoons CO(g) + 3H_2(g)$$
1. Adding both equations: $$CH_4(g) + 2 H_2O(g) + CO_2(g) + H_2(g) \leftrightharpoons CO_2(g) + CO(g) + 4H_2(g) + H_2O(g)$$ Remove the repeated ones. $$CH_4(g) + H_2O(g) \rightleftharpoons CO(g) + 3H_2(g)$$ We need the K value for this reaction. So we can reverse the given equation (CO2(g) ...), and sum them to get the required one.