Beginner Topic 808 of 1102 Organic Chemistry
Carboxylic Acids
Compounds with COOH group, weak acids with strong hydrogen bonding.
In-depth explanation of Carboxylic Acids
Carboxylic acids contain the -COOH group, which combines a carbonyl with a hydroxyl. They are weak acids, with pKa values around 4 to 5, because the carboxylate anion is stabilized by resonance that spreads its negative charge over two oxygen atoms. Carboxylic acids form strong hydrogen-bonded dimers, which give them unusually high boiling points for their molecular mass. They are converted into esters, amides and acid chlorides, which makes them key building blocks in organic synthesis.
Going deeper: Carboxylic Acids
Key ideas: RCOOH, with pKa about 4.8 for acetic acid, acidity enhanced by resonance in the carboxylate and by electron-withdrawing groups. They form hydrogen-bonded dimers, so boiling points are higher than alcohols of similar mass (acetic acid 118 C). Preparations: oxidation of primary alcohols or aldehydes, hydrolysis of nitriles, Grignard plus CO2. React with NaHCO3 giving CO2. Reduced by LiAlH4 but not NaBH4.
Common mistakes and connections: Students expect carboxylic acids to react like ketones at the C=O; the OH makes the carbonyl less electrophilic. Another error is ranking acidity wrongly: chloroacetic acid (2.9) is stronger than acetic, and benzoic acid (4.2) is stronger than acetic acid. Links to esters, acid derivatives and Hell-Volhard-Zelinsky bromination.
Visualization of Carboxylic Acids
Acetic acid shows the planar COOH group with C=O and O-H that forms hydrogen-bonded dimers, giving high boiling points. The interactive lesson shows this as a live animation or chart.
Worked example and use case
Vinegar contains about 5 percent ethanoic acid, which gives it its sour taste.
Frequently asked questions about Carboxylic Acids
What is Carboxylic Acids?
Compounds with COOH group, weak acids with strong hydrogen bonding.
Is Carboxylic Acids a beginner, intermediate or advanced topic?
Carboxylic Acids is a beginner topic in Organic Chemistry. It needs no earlier chemistry lessons and is a good starting point.
What should I learn before Carboxylic Acids?
Study these earlier topics in Organic Chemistry first: Tollens' Test, Fehling's Test, Grignard Reagents.
What comes after Carboxylic Acids?
The next topics in Organic Chemistry are Esters and Esterification.
Can I practise Carboxylic Acids with quizzes?
Yes. The interactive lesson includes a self-check question on Carboxylic Acids, and the Organic Chemistry quiz draws on every topic in this area.
Where Carboxylic Acids fits in Organic Chemistry
Carboxylic Acids is topic 80 of 148 in Organic Chemistry.