It sounds more like a Chemistry question.
When you have an equation of reactants and products that are in an equilibrium, meaning that nothing more is reacting, then adding or subtracting anything to either the products or the reactants can cause a shift in the equilibrium.
When you have an equation of reactants and products that are in an equilibrium, meaning that nothing more is reacting, then adding or subtracting anything to either the products or the reactants can cause a shift in the equilibrium.
