ESTERSifat Ester:Berbau wangi buah-buahan.Tidak larut campur dengan airKurang tumpat daripada air dan terapung di atas air

What are esters?Esters are chemical organic compounds, which are formed when an alcohol reacts with a carboxylic acid. Esters are made by reacting an alcohol with an organic acid. Esters encompass a large family of organic compounds with broad applications in medicine, biology, chemistry and industry.

Structure of esters

FORMULA AM CnH2n + 1COOCmH2m +1

Preparation of estersEsters occur naturally, but can be made in the laboratory by reacting an alcohol with an organic acid. A little sulfuric acid is needed as a catalyst. This is the general word equation for the reaction:

alcohol + organic acid ester + water

For example:

methanol + butanoic acid methyl butanoate + water

The diagram shows how this happens, and where the water comes from:

PENGESTERANSatu campuran asid karboksilik dan alkohol mengalami proses pengesteran apabila dipanaskan bawah refluks bersama asid sulfurik pekat. Kumpulan berfungsi ester ialah kumpulan karboksilat, - COO-

Bahagian asid Bahagian alkohol

Asid karboksilik AlkoholEsterAsid Butanoik PropanolPropil butanoatAsid Etanoik MetanolMetil ethanoatAsid Propanoik EtanolEtil propanoat