What happens to an endothermic reaction when an equilibrium system is heated? the system shifts forward. the system shifts backward. the equilibrium does not shift to maximize the stress. the equilibrium does not shift to restore original conditions.

The system shifts forward.

Explanation:

Any change in the equilibrium is studied on the basis of Le-Chatelier's principle.

This principle states that if there is any change in the variables of the reaction, the equilibrium will shift in the direction to minimize the effect.

If a reaction is endothermic reaction in which heat is absorbed in the reaction.

If the equilibrium system is heated that means the temperature is increased, so according to the Le-Chatlier's principle , the equilibrium will shift in the direction where decrease in temperature occurs. As, the forward reaction is a endothermic reaction, forward reaction will decrease the temperature. Hence, the equilibrium will shift in the forward direction.