Hi Riya,

A+B <->C+D

Some chemical systems become hotter as they react in an insulated container while others become colder, and a some show very little change in temperature.  If the system becomes hotter as the written reaction occurs from left-to-right (the forward reaction), the reaction is said to be exothermic.  Conversely, if the system becomes colder as the forward reaction occurs, the reaction is said to be endothermic.  If the forward reaction is exothermic the reverse reaction will be endothermic, and if the forward reaction is endothermic the reverse reaction will be exothermic.  A reaction that produces no change in temperature in an insulated container is said to be athermal.

We can apply LeChatelier's Principle to a temperature change on a system at equilibrium.  If we try to raise the temperature of this system, the position of equilibrium will shift in the direction that tends to counteract this change - the direction which tends to cool the system: the direction of the endothermic reaction.

Therefore if the reaction is exothermic, an increase in temperature will cause the reverse reaction to occur, decreasing the amounts of the products and increasing the amounts of reactants.  Lowering the temperature will produce the opposite response.

If the reaction is endothermic, an increase in temperature will cause the forward reaction to occur, increasing the amounts of the products and decreasing the amounts of reactants.  Lowering the temperature will produce the opposite response.

Hope this will help you.

Thank You.

Hello,

One direction of a reaction is always exothermic and the other direction is endothermic. The endothermic direction has the larger activation energy. When temperature increases, both rates - forward and reverse increase but the rate of the endothermic reaction increases more.

Hope this helps, Good Luck.