What is resistance? Give its unit?

Explanation

Esterification is the reaction in which esters are formed by reaction between carboxylic acid and an alcohol in the presence of concentrated sulphuric acid
`"Alcohol "+ "Carboxylic acid" to " Ester "+ "water"`
For e.g. Ethanoic acid reacts with ethanol in the presence of an acid catalyst and ester, ethyl ethanoate is formed.
`underset("Ethanol")(C_(2)H_(5)OH)+underset("Ethanoic acid")(CH_(3)COOH )underset("catalyst")overset("acid")to underset(("Ester (ethyl ethanoate"))(CH_(3)COO-C_(2)H_(5))+underset("Water")(H_(2)O)`
Uses: They are used for making fragrances and flavouring agents. e.g.: flavouring in ice-cream and sweets.