Beginner Topic 809 of 1102 Organic Chemistry
Esters
Compounds from acid and alcohol condensation with fruity smells.
In-depth explanation of Esters
Esters have the general formula RCOOR', in which the carbonyl carbon is bonded to an alkoxy group. They are formed from a carboxylic acid and an alcohol, and they have no O-H bond, so they cannot hydrogen bond to one another and have lower boiling points than the parent acids. Many esters have pleasant, fruity odours, which is why they are used in perfumes, flavourings and solvents. Fats and oils are triesters formed from glycerol and three fatty acids.
Going deeper: Esters
Key ideas: RCOOR' have a pleasant fruity smell and are made by esterification or from acid chlorides and anhydrides. They cannot hydrogen bond with themselves, so they boil lower than acids and alcohols of similar mass. Reactions: hydrolysis, reduction by LiAlH4 to two alcohols, transesterification, Grignard to tertiary alcohols, and Claisen condensation. IR C=O stretch at about 1735 per cm.
Common mistakes and connections: Students confuse the name order: ethyl ethanoate has the alcohol-derived group first. Another error is calling esters acidic; they are neutral. Links to esterification equilibrium, saponification, fats as triesters and synthetic flavors.
Visualization of Esters
Isomeric acid and ester: the ester has no O-H to hydrogen bond, so methyl propanoate boils about 85 K lower than butanoic acid. The interactive lesson shows this as a live animation or chart.
Worked example and use case
Ethyl ethanoate has a sweet smell similar to that of nail polish remover.
Frequently asked questions about Esters
What is Esters?
Compounds from acid and alcohol condensation with fruity smells.
Is Esters a beginner, intermediate or advanced topic?
Esters is a beginner topic in Organic Chemistry. It needs no earlier chemistry lessons and is a good starting point.
What should I learn before Esters?
Study these earlier topics in Organic Chemistry first: Fehling's Test, Grignard Reagents, Carboxylic Acids.
What comes after Esters?
The next topics in Organic Chemistry are Esterification and Hydrolysis of Esters.
Can I practise Esters with quizzes?
Yes. The interactive lesson includes a self-check question on Esters, and the Organic Chemistry quiz draws on every topic in this area.
Where Esters fits in Organic Chemistry
Esters is topic 81 of 148 in Organic Chemistry.