Functional groups: classification of organic compounds
International Baccalaureate · IB Diploma · Chemistry · HL Topic 11 3:50 English narration · English + 中文 subtitles burned in
Chapters
Transcript
Two compounds can have the same molecular formula but different structures.
两种化合物可能具有相同的分子式但结构不同。
Their functional groups 官能团 help predict which reactions they undergo.
它们的官能团有助于预测它们会发生哪些反应。
A homologous series shares a functional group and general formula.
同系物具有相同的官能团和通式。
Structural isomers share a molecular formula but differ in atom connections.
结构异构体具有相同的分子式，但原子连接方式不同。
Alkenes contain a carbon-carbon double bond.
烯烃含有碳碳双键。
A functional group is an atom group determining characteristic reactions.
官能团是决定特征反应的原子团。
An isomer is a compound sharing a formula but differing in structure.
异构体是具有相同分子式但结构不同的化合物。
Distinguish addition, substitution, oxidation and polymerization by tracing bonds before and after reaction.
通过追踪反应前后化学键的变化，区分加成、取代、氧化和聚合反应。
Conditions and reagents belong to the reaction arrow; they are not interchangeable labels.
反应条件和试剂位于反应箭头上；它们不是可以互换的标签。
In the lab: Draw displayed or structural formulae with the correct number of bonds at each carbon.
在实验室中，绘制显示式或结构式时，确保每个碳原子具有正确数量的化学键。
Use a carbon count to check a proposed synthesis.
利用碳原子计数来验证所提出的合成路线。
At advanced level, track reagents and conditions through multistep routes.
在高级阶段，需追踪多步反应路线中的试剂与反应条件。
Known: ethene adds bromine across its double bond.
已知：乙烯在双键处与溴发生加成反应。
The two-carbon skeleton stays intact and each carbon gains one bromine atom, giving 1,2-dibromoethane.
两个碳的骨架保持完整，每个碳原子各增加一个溴原子，生成1,2-二溴乙烷。
One mole of ethene reacts with one mole of bromine in this addition reaction.
在此加成反应中，一摩尔乙烯与一摩尔溴反应。
Your turn: How many moles of bromine react completely with 0.15 mol ethene?
请作答：0.15 mol 乙烯完全反应需要消耗多少摩尔的溴？
Bromine decolourization provides evidence of unsaturation in an appropriate test.
溴褪色可作为适当测试中不饱和度的证据。
It is not proof that an unknown sample is specifically ethene.
但这并非证明未知样品具体为乙烯的充分依据。
Not true that compounds with the same molecular formula always have identical properties.
这种说法不正确。 具有相同分子式的化合物并不总是具有相同的性质。
The same molecular formula is not the same compound; isomers such as butane and 2-methylpropane share the formula C 4 H 10 but have different structures and different physical properties.
相同的分子式并不意味着是同一种化合物。 例如，丁烷和 2-甲基丙烷互为同分异构体，分子式都是 C4H10，但结构不同，物理性质也不同。
Structure, not formula alone, sets properties.
决定性质的不是分子式本身，而是结构。
A homologous series shares a functional group and general formula.
同系物具有相同的官能团和通式。
Distinguish addition, substitution, oxidation, and polymerization by tracing bonds before and after reaction.
通过追踪反应前后的化学键，区分加成、取代、氧化和聚合反应。
Watch for: bromine decolourization provides evidence of unsaturation in an appropriate test.
注意：溴褪色可作为适当测试中不饱和度的证据。
Ethene adds bromine in a 1 to 1 mole ratio.
乙烯与溴以1比1的摩尔比发生加成反应。
Find the bromine amount that reacts with 0.25 mol of ethene.
求与0.25 mol乙烯反应的溴的量。
The same molecular formula can belong to different compounds.
相同的分子式可能属于不同的化合物。
The result is 0.25 moles of bromine.
结果是0.25摩尔溴。
Bromine adds across the carbon–carbon double bond of ethene.
溴加成到乙烯的碳碳双键上。
One bromine atom joins each carbon, giving 1,2-dibromoethane, and the orange colour of bromine disappears.
每个碳原子各连接一个溴原子，生成1,2-二溴乙烷，溴的橙色随之消失。
For the reaction of ethene plus bromine yielding 1,2-dibromoethane, we have 0.20 mole of ethene and 0.12 mol of Br2.
对于乙烯与溴反应生成1,2-二溴乙烷的反应，我们有0.20摩尔的乙烯和0.12摩尔的Br2。
Find the product and excess reagent, and explain why this is addition rather than substitution.
请找出产物和过量试剂，并解释为什么这是加成反应而不是取代反应。
The product is 0.12 moles, and 0.08 moles of ethene remain.
产物为0.12摩尔；剩余乙烯为0.08摩尔。
Atoms add across the C=C double bond with no small molecule replaced in this stated reaction.
在此反应中，原子加成在碳碳双键上，且无小分子被取代。
This is a paper model, not an instruction to handle bromine.
这是一个纸模型，并非处理溴的指示。
Retrieve the technical meanings, then vary one input in the original transfer and justify the model condition.
提取技术含义，然后在原始转换中改变一个输入，并论证模型条件。