完全燃烧
醇 → 二氧化碳：查看反应物、产物、反应条件与来源依据，探索相关转化和合成路径。
- 试剂
- 氧
- 条件
- 在过量氧气中点燃
- 反应类别
- 燃烧
- 方程式
- CnH(2n+2)O + (3n/2)O2 -> nCO2 + (n+1)H2O
概览
醇在过量氧气中完全燃烧，生成二氧化碳和水。
转化
- 方程式
- CnH(2n+2)O + (3n/2)O2 -> nCO2 + (n+1)H2O
- 试剂
- 氧
- 反应环境
- 在过量氧气中点燃
- 反应类别
- 燃烧
- 机理
- 燃烧
- Evidence level
- 教材核心内容
参考步骤
Alcohol combustion: energy measurement
Alcohol + oxygen → carbon dioxide + water under complete combustion
物料与用量
- Specified alcohol fuels
- Known mass of water
仪器装置
- Spirit burners with caps
- Balance
- Water container and thermometer
实验步骤
- Keep water mass, burner distance and starting conditions comparable across fuels.
- Measure burner mass loss and water-temperature rise, then express the estimated heat transfer per mole of fuel.
后处理与分离
- Record soot and other evidence of incomplete combustion alongside the numerical result.
关键控制条件
- Heat loss and fuel evaporation usually make the result less exothermic than an ideal combustion value.
- Measure temperature change and analyse combustion gases separately.
- Extinguish and cool burners before handling or refilling; never refill near a flame.
实验技术
Combustion calorimetry and uncertainty
Estimate energy transfer from fuel combustion using water-temperature rise and fuel mass loss.
装置设置
- Measure the water mass and starting temperature, and weigh the capped burner.
- After controlled heating, extinguish the burner, mix the water and record the final temperature and burner mass.
- Use q = mcΔT and divide by moles burned, with a negative sign for the estimated combustion enthalpy.
操作检查
- Heat loss, apparatus heating, evaporation and incomplete combustion affect the estimate.
- Report an experimental value and uncertainty; do not label it a measured standard enthalpy without the required conditions.
底物范围
- 适用范围
- Saturated, acyclic monohydric alcohols undergo complete combustion in excess oxygen to form carbon dioxide and water.
- 来源说明
- The displayed general equation uses the formula CnH(2n+2)O. Other alcohol subclasses require coefficients derived from their own molecular formula; incomplete combustion is not represented here.
相关反应
- Chlorination: Alcohols → Chloroalkanes
醇可转化为氯代烷，为后续取代反应引入更易离去的基团。
- Chlorination with thionyl chloride: Alcohols → Chloroalkanes
氯化亚砜将醇转化为氯代烷，同时生成二氧化硫和氯化氢。
- Bromination: Alcohols → Bromoalkanes
在溴化物和酸的作用下，醇转化为溴代烷。
- Iodination: Alcohols → Iodoalkanes
在碘和红磷的作用下，醇转化为碘代烷。
- Hydrolysis: Chloroalkanes → Alcohols
氢氧根可取代 C-Cl 中的氯，形成醇。
- Hydrolysis: Bromoalkanes → Alcohols
氢氧根可取代 C-Br 中的溴，形成醇。
- Hydrolysis: Iodoalkanes → Alcohols
氢氧根可取代 C-I 中的碘，形成醇。
- Oxidation: Alcohols → Aldehydes
伯醇经受控氧化可生成醛。
- Oxidation: Alcohols → Ketones
仲醇氧化生成酮。
- Oxidation: Alcohols → Carboxylic acids
伯醇充分氧化生成羧酸。
- Hydration: Alkenes → Alcohols
催化水合将烯烃转化为醇。
- Dehydration: Alcohols → Alkenes
脱水将醇转化为烯烃。
- Esterification co reactant: Alcohols → Esters
醇与羧酸结合形成酯。
- Hydrolysis co product: Esters → Alcohols
酯水解也会重新生成相应的醇。
- Grignard carboxylation co reactant: Carbon dioxide → Carboxylic acids
二氧化碳与格氏试剂反应，经酸性后处理得到羧酸。
- Complete combustion: Alkanes → Carbon dioxide
烷烃在过量氧气中完全燃烧，生成二氧化碳和水。
参考文献
- Pearson Edexcel Level 3 Advanced GCE in Chemistry specificationPearson Education Limited · Pearson qualifications · 2024
Supports the textbook-core organic reaction routes used for displayed route and mechanism content.
- Comparing heat energy from burning alcoholsRoyal Society of Chemistry and Nuffield Foundation · RSC Education
Spirit-burner comparisons and post-16 evaluation of heat loss and incomplete combustion.
- Temperature change: combustion of ethanolRoyal Society of Chemistry · RSC Education
Mass loss, water-temperature measurements, energy calculations and experimental evaluation.