# Why is it necessary to heat an esterification reaction?

Why do we heat the mixture acid and alcohol?

The reaction of esterification is exothermic so it is not affected by increasing temperature, then what is the use of heat ?

• reaction of esterification is exothermic, so it is not affected by increasing temperature This is most certainly not true. Increasing the temperature increases the rate for a start and also drives off water which pushes the equilibrium towards the products. – bon May 26 '17 at 17:09

Basically the use of heat is to liberate the water molecule from the mixture of acid and alcohol that is $\ce{OH-}$ ion from alcohol and $\ce{H+}$ from acid that results in formation of ester.Moreover it helps in evaporation of water since esterification reaction forms an equilibrium.The removal of water from mixture forces the reaction to move forward.It helps us to get a large amount of product.Alternative to heating some dehydrating agents like conc. $\ce{H2SO4}$ can also be added.
• $\ce{OH-}$ is a poor leaving group. You don't get hydroxide ions. A better alternative would be to convert the bad leaving group $\ce{OH-}$ into a good leaving group $\ce{H3O+}$. This isn't the true mechanism, however. As far as I know, the $\ce{H+}$ attacks the carbonyl oxygen to produce a geminal alcohol. – Yashas May 31 '17 at 2:15