All of these ideas taken together make up what is known as LeChâtelier's Principle which states that any change made to a system at equilibrium will cause a shift in equilibrium that tends to counteract that change.

Each of the factors examined in this experiment affects the rate of reaction. One additional factor has been omitted: catalysts.

Catalysts speed up the rate of reactions by lowering the activation energy requirement. But this happens for both the forward and reverse reactions so there is no net effect. Another way to think about the behavior of catalysts is in terms of the free energy change. The balanced equation for a reaction is the same with or without the catalyst. Therefore the free energy change is the same with or without the catalyst. That means the extent of spontaneity has not changed.