During the synthesis of esters from carboxylic acids and alcohols, the carboxylic acid is often in excess to push the equilibrium towards the products. This is because it is easier to separate the acid from the product. Describe a method to separate an ester from a carboxylic acid.

FRACTIONAL DISTILLATION separation method

Explanation:

The process by which esters are synthesized involves the reaction between a carboxylic acid and an alcohol. During this process, an excess of one of the reactants which is carboxylic acid is used. This helps to increase the rate of the chemical reaction thereby moving the equilibrium constant of the reaction towards the products.

Excess carboxylic acid mixed with the product of the reaction which is an ester can be separated using FRACTIONAL DISTILLATION separation method. This is a separation method that is used for separation of liquids with close boiling points. Example include components of petroleum, alcohol and water solutions, mixture of esters and carboxylic acids.

The process involves the introduction of a fractionating column between a flask and a condenser. The flask, which contains the impure mixture to be separated, is heated. The vapour of the liquids move into the fractionating column and they are cooled by the glass surface. The liquid with the higher boiling point (less volatile) condenses and falls back into the flask. While the one with the lower boiling point ( more volatile) distils over into the condenser and is collected as the first distillate. The esters has lower boiling point than carboxylic acids, therefore they are collected as the first distillate.

the enthalpy of formation of water is given as -285.8kj/mol, which states that the enthalpy of formation is negative.

negative enthalpy of formation indicates that the heat is released during the reaction process. the heat is released from reaction to the surroundings the enthalpy is expressed with a negative sign with the energy given out in the reaction process.

the formation of water takes place by giving out heat which is -285.8 kj/mol.