Explain the following processess with the help of chemical reactions : (a) Esterification (b) Saponification (c ) Hydrogenation.

Explain the following processess with the help of chemical reactions :

1.	Explain the following processess with the help of chemical reactions : (a) Esterification (b) Saponification (c ) Hydrogenation.
Answer» Solution :(a) Esterification. It is the process in which a carboxylic acid reacts with an alcohol in the presence of some mineral acid to give ESTER and water. Example : `underset("Ethanol")(CH_(3)CH_(2)OH) + underset("Ethanoic acid")(CH_(3)COOH) overset("Acid")rarr underset("Ethyl ethanoate")(CH_(3)CH_(2)OOC CH_(3)) + H_(2)O` (b) saponification. It is the process used for forming soap. In this process an ester is heated with alkali (NaOH or KOH) to give sodium salt of carboxylic acid and alcohol. For example when ethyl\ ethanoate is boiled with a solution of sodium hydroxide, sodium ethanoate and ethanol are produced. `underset("Ethylethanoate")(CH_(3)COOC_(2)H_(5)) + NaOH overset("Boiled")rarr underset("Sod.ethanoate")(CH_(3)COONa) + underset("Ethanol")(C_(2)H_(5)OH)` (c ) Hydrogenation. it is a process involving addition of hydrogen. it changes unsaturated compounds to saturated compounds. It also CAUSES REDUCTION of many organic compounds. `underset("Ethene")(CH_(2)) = CH_(2) + H_(2) overset(Ni)rarr underset("Ethane")(CH_(3) - CH_(3))` `underset("Ethene")(CH) -= CH + 2H_(2) overset(Ni)rarr underset("Ethane")(CH_(3) - CH_(3))` `underset("Ethanoic acid")(CH_(3)COOH) + H_(2) + H_(2) overset(Ni)rarr underset("Ethanol")(CH_(3)CH_(2))`