有机化学是碳化合物的化学。碳特殊,因为它能与其他碳原子连接以构成长链和环。
有机化学
IGCSE 化学 · 第 11 主题
11.1
化学式、官能团与术语
大纲
| Core | Supplement |
|---|---|
| 1 Draw and interpret the displayed formula of a molecule to show all the atoms and all the bonds | |
| 2 Write and interpret general formulae of compounds in the same homologous series, limited to: (a) alkanes, $\text{C}_n\text{H}_{2n+2}$ (b) alkenes, $\text{C}_n\text{H}_{2n}$ (c) alcohols, $\text{C}_n\text{H}_{2n+1}\text{OH}$ (d) carboxylic acids, $\text{C}_n\text{H}_{2n+1}\text{COOH}$ | |
| 3 Identify a functional group as an atom or group of atoms that determine the chemical properties of a homologous series | |
| 7 State that a structural formula is an unambiguous description of the way the atoms in a molecule are arranged, including $\text{CH}_2=\text{CH}_2$, $\text{CH}_3\text{CH}_2\text{OH}$, $\text{CH}_3\text{COOCH}_3$ | |
| 8 Define structural isomers as compounds with the same molecular formula, but different structural formulae, including $\text{C}_4\text{H}_{10}$ as $\text{CH}_3\text{CH}_2\text{CH}_2\text{CH}_3$ and $\text{CH}_3\text{CH}(\text{CH}_3)\text{CH}_3$ and $\text{C}_4\text{H}_8$ as $\text{CH}_3\text{CH}_2\text{CH}=\text{CH}_2$ and $\text{CH}_3\text{CH}=\text{CHCH}_3$ | |
| 4 State that a homologous series is a family of similar compounds with similar chemical properties due to the presence of the same functional group | 9 Describe the general characteristics of a homologous series as: (a) having the same functional group (b) having the same general formula (c) differing from one member to the next by a –CH2– unit (d) displaying a trend in physical properties (e) sharing similar chemical properties |
| 5 State that a saturated compound has molecules in which all carbon–carbon bonds are single bonds | |
| 6 State that an unsaturated compound has molecules in which one or more carbon–carbon bonds are not single bonds |
来源:剑桥国际大纲
有几种书写一个有机分子的方式:
- 分子式(molecular formula)显示每种原子有多少个,例如 $\text{C}_2\text{H}_6$。
- 结构式(displayed formula)完整地画出每个原子和每个键。
- 结构简式(structural formula)在不画每个键的情况下显示原子如何排列,例如 $\text{CH}_3\text{CH}_2\text{OH}$。
- 通式(general formula)对一整个家族有效,例如烷烃的 $\text{C}_n\text{H}_{2n+2}$。
一个同系物(homologous series)是有相同官能团(functional group)的一个化合物家族——给这个家族它化学性质的原子或原子团。一个系列的成员有相同的通式、每一步相差一个 $\text{CH}_2$ 单元,并有相似的化学性质、物理性质逐渐变化。
| 系列 | 官能团 | 通式 |
|---|---|---|
| 烷烃 | 只有 C–C 单键 | $\text{C}_n\text{H}_{2n+2}$ |
| 烯烃 | C=C 双键 | $\text{C}_n\text{H}_{2n}$ |
| 醇 | –OH | $\text{C}_n\text{H}_{2n+1}\text{OH}$ |
| 羧酸 | –COOH | $\text{C}_n\text{H}_{2n+1}\text{COOH}$ |
一个饱和(saturated)化合物只有碳–碳单键。一个不饱和(unsaturated)化合物有一个或多个不是单键的碳–碳键(如一个 C=C 双键)。
同分异构体(structural isomers)是有相同分子式但不同结构简式的化合物。例如,$\text{C}_4\text{H}_{10}$ 能是一个直链或一个支链。
探索
Functional group lab
Classify organic molecules by the group that controls their reactions.
词汇表
训练
| 英文 | 中文 | 拼音 |
|---|---|---|
| molecular formula | 分子式 | fēn zǐ shì |
| displayed formula | 结构式 | jié gòu shì |
| structural formula | 结构简式 | jié gòu jiǎn shì |
| general formula | 通式 | tōng shì |
| homologous series | 同系物 | tóng xì wù |
| functional group | 官能团 | guān néng tuán |
| saturated | 饱和 | bǎo hé |
| unsaturated | 不饱和 | bù bǎo hé |
| Structural isomers | 同分异构体 | tóng fēn yì gòu tǐ |
11.2
有机化合物的命名
大纲
| Core | Supplement |
|---|---|
| 1 Name and draw the displayed formulae of: (a) methane and ethane (b) ethene (c) ethanol (d) ethanoic acid (e) the products of the reactions stated in sections 11.4–11.7 | 3 Name and draw the structural and displayed formulae of unbranched: (a) alkanes (b) alkenes, including but-1-ene and but-2-ene (c) alcohols, including propan-1-ol, propan-2-ol, butan-1-ol and butan-2-ol (d) carboxylic acids containing up to four carbon atoms per molecule |
| 2 State the type of compound present, given a chemical name ending in -ane, -ene, -ol, or -oic acid or from a molecular formula or displayed formula | 4 Name and draw the displayed formulae of the unbranched esters which can be made from unbranched alcohols and carboxylic acids, each containing up to four carbon atoms |
来源:剑桥国际大纲
名称的结尾告诉你家族:
| 结尾 | 家族 | 例子 |
|---|---|---|
| -ane | 烷烃 | 甲烷、乙烷 |
| -ene | 烯烃 | 乙烯 |
| -ol | 醇 | 乙醇 |
| -oic acid | 羧酸 | 乙酸 |
名称的开头告诉你碳原子的数目:meth- = 1、eth- = 2、prop- = 3、but- = 4。对于更长的烯烃和醇,一个数字显示官能团在哪里,例如 but-1-ene 和 but-2-ene,或 propan-1-ol 和 propan-2-ol。
探索
Organic naming route
Follow the route from structure to systematic name.
11.3
燃料
大纲
| Core | Supplement |
|---|---|
| 1 Name the fossil fuels: coal, natural gas and petroleum | |
| 2 Name methane as the main constituent of natural gas | |
| 3 State that hydrocarbons are compounds that contain hydrogen and carbon only | |
| 4 State that petroleum is a mixture of hydrocarbons | |
| 5 Describe the separation of petroleum into useful fractions by fractional distillation | |
| 6 Describe how the properties of fractions obtained from petroleum change from the bottom to the top of the fractionating column, limited to: (a) decreasing chain length (b) higher volatility (c) lower boiling points (d) lower viscosity | |
| 7 Name the uses of the fractions as: (a) refinery gas fraction for gas used in heating and cooking (b) gasoline/petrol fraction for fuel used in cars (c) naphtha fraction as a chemical feedstock (d) kerosene/paraffin fraction for jet fuel (e) diesel oil/gas oil fraction for fuel used in diesel engines (f) fuel oil fraction for fuel used in ships and home heating systems (g) lubricating oil fraction for lubricants, waxes and polishes (h) bitumen fraction for making roads |
来源:剑桥国际大纲
三种化石燃料(fossil fuels)是煤(coal)、天然气(natural gas)和石油(petroleum,原油)。甲烷(methane)是天然气的主要部分。
一个碳氢化合物(hydrocarbon)是一个只由氢和碳构成的化合物。石油是许多不同碳氢化合物的一个混合物。
Fractional distillation
石油通过分馏(fractional distillation)被分离成有用的馏分(fractions)。混合物被加热,而不同的碳氢化合物变成气体并沿一个高的分馏塔(fractionating column)上升。塔在底部热而在顶部凉,所以每个馏分在一个不同的高度变回液体。
从塔的底部到顶部,这些馏分有:
- 更短的链长(chain length,更小的分子);
- 更高的挥发性(volatility,它们更容易变成气体);
- 更低的沸点;
- 更低的黏度(viscosity,它们更容易流动)。
| 馏分 | 用途 |
|---|---|
| 炼厂气 | 供暖和烹饪的气体 |
| 汽油 | 汽车的燃料 |
| 石脑油 | 制造化学品的原料 |
| 煤油 | 喷气燃料 |
| 柴油 | 柴油发动机的燃料 |
| 燃料油 | 船只和家庭供暖的燃料 |
| 润滑油 | 润滑剂、蜡和抛光剂 |
| 沥青(bitumen) | 修路 |
探索
Fuel chain lab
Follow a fuel from source to combustion products.
词汇表
训练
| 英文 | 中文 | 拼音 |
|---|---|---|
| fossil fuels | 化石燃料 | huà shí rán liào |
| coal | 煤 | méi |
| natural gas | 天然气 | tiān rán qì |
| petroleum | 石油 | shí yóu |
| Methane | 甲烷 | jiǎ wán |
| hydrocarbon | 碳氢化合物 | tàn qīng huà hé wù |
| fractions | 馏分 | liú fèn |
| fractional distillation | 分馏 | fēn liú |
| fractionating column | 分馏塔 | fēn liú tǎ |
| chain length | 链长 | liàn zhǎng |
| volatility | 挥发性 | huī fā xìng |
| viscosity | 黏度 | nián dù |
| bitumen | 沥青 | lì qīng |
11.4
烷烃
大纲
| Core | Supplement |
|---|---|
| 1 State that the bonding in alkanes is single covalent and that alkanes are saturated hydrocarbons | |
| 2 Describe the properties of alkanes as being generally unreactive, except in terms of combustion and substitution by chlorine | 3 State that in a substitution reaction one atom or group of atoms is replaced by another atom or group of atoms |
| 4 Describe the substitution reaction of alkanes with chlorine as a photochemical reaction, with ultraviolet light providing the activation energy, $E_a$, and draw the structural or displayed formulae of the products, limited to monosubstitution |
来源:剑桥国际大纲
烷烃(alkanes)只有单共价键,所以它们是饱和碳氢化合物。它们通常不活泼。它们两个重要的反应是:
- 燃烧(combustion):它们在大量的氧气中燃烧以给出二氧化碳和水。
- 与氯的取代。
在一个取代反应(substitution reaction)中,一个原子(或原子团)被另一个替换。烷烃只在紫外线(ultraviolet light)中与氯反应——这是一个光化学反应(photochemical reaction),光提供活化能(activation energy)。例如:
$$\text{CH}_4 + \text{Cl}_2 \rightarrow \text{CH}_3\text{Cl} + \text{HCl}$$
探索
Burning an alkane
Step through combustion. With plenty of oxygen an alkane burns cleanly; starve it of oxygen and you get toxic carbon monoxide and soot instead.
词汇表
训练
| 英文 | 中文 | 拼音 |
|---|---|---|
| Alkanes | 烷烃 | wán tīng |
| Combustion | 燃烧 | rán shāo |
| substitution reaction | 取代反应 | qǔ dài fǎn yìng |
| ultraviolet light | 紫外线 | zǐ wài xiàn |
| photochemical reaction | 光化学反应 | guāng huà xué fǎn yìng |
| activation energy | 活化能 | huó huà néng |
11.5
烯烃
大纲
| Core | Supplement |
|---|---|
| 1 State that the bonding in alkenes includes a double carbon–carbon covalent bond and that alkenes are unsaturated hydrocarbons | |
| 2 Describe the manufacture of alkenes and hydrogen by the cracking of larger alkane molecules using a high temperature and a catalyst | |
| 3 Describe the reasons for the cracking of larger alkane molecules | |
| 5 State that in an addition reaction only one product is formed | |
| 4 Describe the test to distinguish between saturated and unsaturated hydrocarbons by their reaction with aqueous bromine | 6 Describe the properties of alkenes in terms of addition reactions with: (a) bromine or aqueous bromine (b) hydrogen in the presence of a nickel catalyst (c) steam in the presence of an acid catalyst and draw the structural or displayed formulae of the products |
来源:剑桥国际大纲
烯烃(alkenes)有一个碳–碳双键(C=C),所以它们是不饱和碳氢化合物。
Cracking
大烷烃分子不太有用。裂化(cracking)用一个高温和一个催化剂(catalyst)把它们分解成更小、更有用的分子——更小的烷烃和烯烃。裂化也制造氢气(hydrogen)并提供制造塑料的烯烃。
例题。 裂化一个癸烷分子 $\text{C}_{10}\text{H}_{22}$,得到辛烷 $\text{C}_8\text{H}_{18}$ 和另外一种产物。指出它是什么,并说明你如何区分这两种产物。原子是守恒的,所以做减法:碳 $10 - 8 = 2$,氢 $22 - 18 = 4$。另一种产物是 $\text{C}_2\text{H}_4$,即乙烯 - 一种烯烃,因为它符合 $\text{C}_n\text{H}_{2n}$。要区分它们,把每一种与橙色的溴水振荡:乙烯有 C=C,所以能使溴水褪色,而辛烷是饱和的,溴水仍是橙色。裂化方程式靠数两边的原子来配平;剩下的那部分就是烯烃。
Reactions of alkenes
C=C 双键使烯烃活泼。它们参与加成反应(addition reactions),两个分子连接以构成一个单一的生成物。
- 不饱和的测试:把化合物与溴(bromine)水(它是橙色的)摇动。一个烯烃使溴水变无色;一个烷烃不改变它。
- 与氢和一个镍(nickel)催化剂,一个烯烃变成一个烷烃。
- 与蒸汽(steam)和一个酸催化剂,一个烯烃变成一个醇。
探索
Addition across the C=C double bond
Step through an addition reaction. The C=C double bond is an alkene's reactive spot — molecules add right across it, which also gives the bromine-water test.
词汇表
训练
| 英文 | 中文 | 拼音 |
|---|---|---|
| Alkenes | 烯烃 | xī tīng |
| Cracking | 裂化 | liè huà |
| catalyst | 催化剂 | cuī huà jì |
| hydrogen | 氢气 | qīng qì |
| addition reactions | 加成反应 | jiā chéng fǎn yìng |
| bromine | 溴 | xiù |
| nickel | 镍 | niè |
| steam | 蒸汽 | zhēng qì |
11.6
醇
大纲
| Core | Supplement |
|---|---|
| 1 Describe the manufacture of ethanol by: (a) fermentation of aqueous glucose at 25–35 °C in the presence of yeast and in the absence of oxygen (b) catalytic addition of steam to ethene at 300 °C and 6000 kPa / 60 atm in the presence of an acid catalyst | 4 Describe the advantages and disadvantages of the manufacture of ethanol by: (a) fermentation (b) catalytic addition of steam to ethene |
| 2 Describe the combustion of ethanol | |
| 3 State the uses of ethanol as: (a) a solvent (b) a fuel |
来源:剑桥国际大纲
醇(alcohols)含有 –OH 官能团。最重要的一个是乙醇(ethanol)。有两种制造乙醇的方式。
| 方法 | 条件 | 注释 |
|---|---|---|
| 葡萄糖的发酵(fermentation) | 酵母、25–35 °C、无氧气 | 用可再生的糖,但慢并给出不纯的乙醇 |
| 向乙烯(ethene)加蒸汽 | 300 °C、60 atm、酸催化剂 | 快而纯,但用石油(不可再生) |
在发酵中,酵母(yeast)把葡萄糖(glucose)变成乙醇和二氧化碳。
乙醇燃烧得好(燃烧),所以它被用作一种燃料。它也溶解许多物质,所以它被用作一种溶剂(solvent)。
探索
Making ethanol by fermentation
Step through fermentation. Yeast turns sugar into ethanol with no air — the same alcohol can then be oxidised to vinegar.
词汇表
训练
| 英文 | 中文 | 拼音 |
|---|---|---|
| Alcohols | 醇 | chún |
| ethanol | 乙醇 | yǐ chún |
| fermentation | 发酵 | fā jiào |
| ethene | 乙烯 | yǐ xī |
| yeast | 酵母 | jiào mǔ |
| glucose | 葡萄糖 | pú táo táng |
| solvent | 溶剂 | róng jì |
11.7
羧酸
大纲
| Core | Supplement |
|---|---|
| 1 Describe the reaction of ethanoic acid with: (a) metals (b) bases (c) carbonates including names and formulae of the salts produced | 2 Describe the formation of ethanoic acid by the oxidation of ethanol: (a) with acidified aqueous potassium manganate(VII) (b) by bacterial oxidation during vinegar production |
| 3 Describe the reaction of a carboxylic acid with an alcohol using an acid catalyst to form an ester |
来源:剑桥国际大纲
羧酸(carboxylic acids)含有 –COOH 官能团。乙酸(ethanoic acid)是要知道的那个。像其他酸,它与以下反应:
- 金属(metals)→ 一个盐 + 氢气;
- 碱(bases)→ 一个盐(salt)+ 水;
- 碳酸盐(carbonates)→ 一个盐 + 水 + 二氧化碳。
构成的盐叫乙酸盐。
乙酸能通过乙醇的氧化(oxidation)制造,要么用酸化的高锰酸钾(potassium manganate(VII)),要么由细菌在制造醋(vinegar)期间。
当一个羧酸与一个醇反应时(用一个酸催化剂),它构成一个酯(ester)。例如,乙醇 + 乙酸 → 乙酸乙酯 + 水。酯的官能团是 $-\text{COO}-$,你从它的两个母体命名它:醇给出第一部分,带 -yl(基)结尾(乙基 ethyl),酸给出第二部分,带 -oate(酸酯)结尾(乙酸酯 ethanoate)。它的示性式是 $\text{CH}_3\text{-COO-CH}_2\text{-CH}_3$。
探索
A weak acid's pH
Carboxylic acids are weak acids — they only partly ionise, so they sit just below pH 7. Slide the scale to see where they fall.
词汇表
训练
| 英文 | 中文 | 拼音 |
|---|---|---|
| Carboxylic acids | 羧酸 | suō suān |
| Ethanoic acid | 乙酸 | yǐ suān |
| metals | 金属 | jīn shǔ |
| bases | 碱 | jiǎn |
| salt | 盐 | yán |
| carbonates | 碳酸盐 | tàn suān yán |
| oxidation | 氧化 | yǎng huà |
| potassium manganate(VII) | 高锰酸钾 | gāo měng suān jiǎ |
| vinegar | 醋 | cù |
| ester | 酯 | zhǐ |
11.8
聚合物
大纲
| Core | Supplement |
|---|---|
| 1 Define polymers as large molecules built up from many smaller molecules called monomers | 6 Identify the repeat units and/or linkages in addition polymers and in condensation polymers |
| 2 Describe the formation of poly(ethene) as an example of addition polymerisation using ethene monomers | 7 Deduce the structure or repeat unit of an addition polymer from a given alkene and vice versa |
| 8 Deduce the structure or repeat unit of a condensation polymer from given monomers and vice versa, limited to: (a) polyamides from a dicarboxylic acid and a diamine (b) polyesters from a dicarboxylic acid and a diol | |
| 9 Describe the differences between addition and condensation polymerisation | |
| 10 Describe and draw the structure of: (a) nylon, a polyamide [image] (b) PET, a polyester [image] The full name for PET, polyethylene terephthalate, is not required | |
| 3 State that plastics are made from polymers | |
| 4 Describe how the properties of plastics have implications for their disposal | 11 State that PET can be converted back into monomers and re-polymerised |
| 5 Describe the environmental challenges caused by plastics, limited to: (a) disposal in landfill sites (b) accumulation in oceans (c) formation of toxic gases from burning | |
| 12 Describe proteins as natural polyamides and that they are formed from amino acid monomers with the general structure: [image] where R represents different types of side-chain | |
| 13 Describe and draw the structure of proteins as: [image] |
来源:剑桥国际大纲
一个聚合物(polymer)是一个从许多叫单体(monomers)的小分子构建的非常大的分子。
Addition polymerisation
在加聚(addition polymerisation)中,许多不饱和单体连接在一起而没有其他生成物。例如,许多乙烯单体连接以制造聚乙烯。沿链重复的小部分是重复单元(repeat unit)。
Condensation polymerisation
在缩聚(condensation polymerisation)中,单体连接,而每次一个键形成时失去一个小分子(通常是水)。这制造两种重要的类型:
- 聚酰胺(polyamides)由一个二羧酸和一个二胺制造。尼龙(nylon)是一种聚酰胺。
- 聚酯(polyesters)由一个二羧酸和一个二醇制造。PET 是一种聚酯,而且它能被分解回它的单体并重新制造。
连接单体的新键是连接键:在尼龙等聚酰胺里是一个酰胺键 $-\text{CO-NH}-$(amide linkage),在 PET 等聚酯里是一个酯键 $-\text{CO-O}-$(ester linkage)。一个重复单元画在括号里,例如尼龙是 $-[\text{CO-}(\text{CH}_2)_4\text{-CO-NH-}(\text{CH}_2)_6\text{-NH}]-$;考试里你可能被要求在一个画出的重复单元上圈出连接键。
Plastics and the environment
塑料(plastics)由聚合物制造。因为许多塑料不分解,处理它们是一个问题:
- 它们在填埋(landfill)场积累;
- 它们在海洋中聚集并伤害海洋生物;
- 烧它们能制造有毒气体。
Proteins
蛋白质(proteins)是天然的聚酰胺。它们由连接成长链的氨基酸(amino acid)单体制造。
探索
Making a polymer
Small monomers join into a long chain — the basis of all plastics.
词汇表
训练
| 英文 | 中文 | 拼音 |
|---|---|---|
| polymer | 聚合物 | jù hé wù |
| monomers | 单体 | dān tǐ |
| addition polymerisation | 加聚 | jiā jù |
| repeat unit | 重复单元 | chóng fù dān yuán |
| condensation polymerisation | 缩聚 | suō jù |
| Polyamides | 聚酰胺 | jù xiān àn |
| Nylon | 尼龙 | ní lóng |
| Polyesters | 聚酯 | jù zhǐ |
| amide linkage | 酰胺键 | xiān àn jiàn |
| ester linkage | 酯键 | zhǐ jiàn |
| Plastics | 塑料 | sù liào |
| landfill | 填埋 | tián mái |
| Proteins | 蛋白质 | dàn bái zhì |
| amino acid | 氨基酸 | ān jī suān |
11.8
考试技巧
- 按官能团和通式学习每个同系物:烷烃 $\text{C}_n\text{H}_{2n+2}$、烯烃 $\text{C}_n\text{H}_{2n}$、醇 $-\text{OH}$、羧酸 $-\text{COOH}$。
- 不饱和的溴水测试:一个烯烃(带它的 C=C)使橙色溴水变无色;一个烷烃使它保持橙色。
- 裂化用热和一个催化剂把大的、不太有用的烷烃分解成更小的烷烃和烯烃。
- 到乙醇的两条路线:葡萄糖的发酵(可再生但慢而不纯)和向乙烯加蒸汽(快而纯,但来自石油)。
- 加聚连接不饱和单体而没有其他生成物;缩聚连接单体并每次失去一个小分子(通常是水)。
本主题的互动课程
逐步学习,并即时检测练习。