Consider the chemical equation in equilibrium. ch4(g) + h2o(g) mc004-1.jpg co(g) + 3h2(g) what will happen to the equilibrium of this reaction if co is added to the system? the equilibrium will shift to the left to favor the reverse reaction. the equilibrium will shift to the right to favor the forward reaction. the equilibrium will not be affected by changing the concentration of co. the equilibrium in the system will be lost under this kind of stress.

The equilibrium will shift to the left to favor the reverse reaction.

Explanation:

This is a direct application of Le Chatelier's principle.

Le Chatelier's principle states: if it is introduced a change that distrubs a system in equilibrium, the system will displace toward the direction that release the disturbance.

The increase in the concentration of CO (which is in the right side of the equation) takes the system out of the equilibrium. The greater number of molecules of CO means that more CO will react to favor the reverse reaction and restore the equilibrium with the increase of molecules in the left side.