Where does the water come from when methyl propanoate forms? What is the formula of the ester?
The water comes from the OH of the acid and the H of the alcohol. The formula of the ester is CH₃CH₂C(=O)-OCH₃.
Propanoic acid reacts with methanol in the presence of concentrated sulfuric acid to form methyl propanoate. Concentrated sulfuric acid catalyzes the reaction.