A

Aldehyde

R-CHO (general); e.g., HCHO, CH₃CHO
Quick Reference
Formula / NotationR-CHO (general); e.g., HCHO, CH₃CHO
Also Known AsAlkanal; carbonyl compound (terminal); –CHO functional group; formyl group (HCO–)

What is Aldehyde?

Aldehydes are organic compounds containing a carbonyl group (C=O) bonded to at least one hydrogen atom, giving the characteristic –CHO functional group at the end of a carbon chain. Aldehydes are named with the suffix -al (e.g., methanal, ethanal). They are intermediate in oxidation state between alcohols and carboxylic acids.

Formula & Notation

R-CHO (general); e.g., HCHO, CH₃CHO

Other Names / Synonyms: Alkanal; carbonyl compound (terminal); –CHO functional group; formyl group (HCO–)

Properties & Characteristics

General formula: R-CHO; IUPAC suffix: -al; carbonyl at terminal position; easily oxidised to carboxylic acids (by KMnO₄, Tollens' reagent); reduced to primary alcohols; undergo nucleophilic addition; give positive Tollens' and Fehling's tests; pungent or fruity odour

Uses & Applications

Manufacture of resins, plastics, and dyes (formaldehyde, acetaldehyde); flavouring agents and perfumes; chemical intermediates in synthesis; preservatives (formaldehyde solution/formalin); vanillin (food flavour); glutaraldehyde as disinfectant

Safety Information

Many aldehydes are toxic and irritating — formaldehyde is a known human carcinogen (IARC Group 1) and strong sensitiser. Acetaldehyde is flammable and suspected carcinogen. Use in well-ventilated areas or fume hood. Wear appropriate PPE. Store away from oxidisers.

Always consult the SDS/MSDS before handling any chemical. This information is for educational purposes only.

Key Facts

Term Aldehyde
Formula R-CHO (general); e.g., HCHO, CH₃CHO
Synonyms Alkanal; carbonyl compound (terminal); –CHO functional group; formyl group (HCO–)

Frequently Asked Questions

Aldehydes are organic compounds containing a carbonyl group (C=O) bonded to at least one hydrogen atom, giving the characteristic –CHO functional group at the end of a carbon chain. Aldehydes are named with the suffix -al (e.g., methanal, ethanal). They are intermediate in oxidation state between alcohols and carboxylic acids.

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