乙醛
乙醛是能够发生碘仿反应的醛类特例，其羰基旁连接甲基，具有所需的 CH3CO- 结构。
- 化学式
- C2H4O
- 官能团
- CH3CHO
- 摩尔质量
- 44.05 g/mol
- Also known as
- acetaldehyde, CH3CHO
概览
Two-carbon aldehyde that gives the iodoform reaction.
Identifiers
- 化学式
- C2H4O
- 官能团
- CH3CHO
- 摩尔质量
- 44.05 g/mol
- Also known as
- acetaldehyde, CH3CHO
化学标识符
- SMILES
- CC=O
- InChI
- InChI=1S/C2H4O/c1-2-3/h2H,1H3
- PubChem CID
- 177
性质
- 熔点
- -123.4 °C
- 沸点
- 20.8 °C
- 密度
- 0.7834 g/cu cm at 18 °C
- 水中溶解度
- Miscible with water
Diagnostic tests
碘仿试验
- 试剂
- 碱性碘溶液
- 条件
- 先加入碘，再加入碱的水溶液，随后在水浴中温和加热。
- Positive observation
- 生成淡黄色三碘甲烷沉淀
- Negative observation
- 不生成淡黄色沉淀
- Interpretation
- 阳性结果与乙醛相符；乙醛是能发生碘仿反应的醛。
- 适用范围
- 乙醛是碘仿试验阳性物质中的醛类成员。
- 来源说明
- 并非乙醛特有：乙醇、甲基酮和含 CH3CH(OH)- 结构的仲醇也会呈阳性。
- 证据
- 教材核心内容
Related compounds
- 醛
Ethanal is a two-carbon molecule-level member of the aldehyde family.
Connected reactions
- Iodoform reaction: Ethanal → Triiodomethane 个产物
乙醛在碱性碘溶液中发生碘仿反应，生成三碘甲烷和甲酸盐。
- Partial oxidation: Ethanol → Ethanal
乙醇氧化为乙醛。
- Oxidation: Ethanal → Ethanoic acid
乙醛氧化为乙酸。
- Reduction: Ethanal → Ethanol
乙醛还原为乙醇。
参考文献
- PubChem Compound Summary for AcetaldehydeNational Center for Biotechnology Information · PubChem · 2026
Used for stable identifiers and basic compound metadata.
- Hazardous Substances Data Bank (HSDB): Ethanal — melting pointHazardous Substances Data Bank (HSDB)
Retrieved through PubChem PUG View on 2026-09-08. https://pubchem.ncbi.nlm.nih.gov/compound/177#section=Melting-Point. Source value, complete property clause or compact miscibility statement retained; absent pressure, temperature or phase conditions are not inferred. Original reference: Haynes, W.M. (ed.). CRC Handbook of Chemistry and Physics. 95th Edition. CRC Press LLC, Boca Raton: FL 2014-2015, p. 3-4
- Hazardous Substances Data Bank (HSDB): Ethanal — boiling pointHazardous Substances Data Bank (HSDB)
Retrieved through PubChem PUG View on 2026-09-08. https://pubchem.ncbi.nlm.nih.gov/compound/177#section=Boiling-Point. Source value, complete property clause or compact miscibility statement retained; absent pressure, temperature or phase conditions are not inferred. Original reference: Haynes, W.M. (ed.). CRC Handbook of Chemistry and Physics. 95th Edition. CRC Press LLC, Boca Raton: FL 2014-2015, p. 3-4
- Hazardous Substances Data Bank (HSDB): Ethanal — densityHazardous Substances Data Bank (HSDB)
Retrieved through PubChem PUG View on 2026-09-08. https://pubchem.ncbi.nlm.nih.gov/compound/177#section=Density. Source value, complete property clause or compact miscibility statement retained; absent pressure, temperature or phase conditions are not inferred. Original reference: Haynes, W.M. (ed.). CRC Handbook of Chemistry and Physics. 95th Edition. CRC Press LLC, Boca Raton: FL 2014-2015, p. 3-4
- ILO-WHO International Chemical Safety Cards (ICSCs): Ethanal — solubilityILO-WHO International Chemical Safety Cards (ICSCs)
Retrieved through PubChem PUG View on 2026-09-08. https://pubchem.ncbi.nlm.nih.gov/compound/177#section=Solubility. Source value, complete property clause or compact miscibility statement retained; absent pressure, temperature or phase conditions are not inferred.
- Pearson Edexcel International Advanced Level Chemistry Practical GuidePearson Education Limited · Pearson qualifications · 2018
Official Pearson practical guidance for organic qualitative tests, including bromine water, acidified dichromate, silver nitrate, carbonyl reagents and the iodoform reaction.