Question

The endothermic reaction ($M+N\rightleftharpoons P$) is allowed to obtain an equilibrium at ${{25}^{o}}C$. Formation of $P$can be increased by [BHU$1981$]
A.Raising temperature
B.Lowering temperature
C.Keeping temperature constant
D.Decreasing the concentration of $M$and $N$

Answer 1

Hint: The endothermic reaction is one in which reactants absorb energy from outside to form the products. Here in this case temperature decreases which causes stress in the system. Hence the system will try to shift the equilibrium in the direction so that it can neutralize the changes.

Complete answer:Any change in pressure, concentration, and temperature in a chemical system result in an equilibrium shift to oppose the change until a new equilibrium is reached i.e, Le-Chatelier’s principle refers to the process of disturbance and re-establishment of equilibrium.

 Now if a system is endothermic, that means it absorbs heat as it moves forward, and decreasing the temperature of the reaction leads to a shift to the right. An increase in temperature raises the amount of heat in the system. Hence the system tries to remove the excess heat by absorption i.e an endothermic reaction.

According to Le-Chatelier’s principle, the system will try to compensate for the raising temperature and the equilibrium will shift toward the forward direction which means the system will favor endothermic reactions, the direction with positive $\Lambda {{H}^{O}}$.
Therefore, according to Le-Chatelier’s principle in the endothermic reaction, the formation of $P$can be increased by raising the temperature.

Thus, option (A) is correct.

Note: The overall equilibrium of the reaction can be changed if the reaction is exothermic. In that case decrease in the temperature of the system favors. During this temperature change, the overall reaction system establishes a new equilibrium in which the equilibrium constant value will be different from the original value.