Question

In a reversible reaction, some amount of heat energy is liberated in the forward reaction. Name the reaction. What change in temperature favours the forward reactions?

Answer 1

In a reversible reaction, evolution of heat energy indicates that it is an exothermic reaction and $\Delta H=-ve$. In exothermic reactions, heat is released with the products. When separated molecules join together, enough energy is released to overcompensate for the energy required to break reactant bonds.

For example $A+B\rightleftharpoons C+D+Energy$

Hence, the low temperature favours the formation of products. If the temperature is increased the equilibrium will shift to the left (using Le Chatelier's principle). If temperature is decreased, the reaction will proceed forward to produce more heat (which is lacking). The effect of temperature on equilibrium will also change the value of the equilibrium constant.