Alkanes · 烷烃
| English | 中文 | Pinyin · 拼音 |
|---|---|---|
| alkane/ˈælkeɪn/ | 烷烃 | wán tīng |
| saturated/ˈsætʃəreɪtɪd/ | 饱和 | bǎo hé |
| hydrogenation/haɪˈdrɒdʒəneɪʃn/ | 氢化 | qīng huà |
| cracking/ˈkrækɪŋ/ | 裂化 | liè huà |
| combustion/kəmˈbʌstʃn/ | 燃烧 | rán shāo |
| carbon monoxide/ˈkɑːbən mʌˈnɒksaɪd/ | 一氧化碳 | yī yǎng huà tàn |
The unreactive backbone
- Alkanes 烷烃 are saturated 饱和 hydrocarbons ($\text{C}_n\text{H}_{2n+2}$).
- They are useful fuels but generally unreactive.
- We make them and burn them.
不活泼的骨架
- 烷烃(alkanes)是饱和碳氢化合物($\text{C}_n\text{H}_{2n+2}$)。
- 它们是有用的燃料,但通常不活泼。
- 我们制造它们并燃烧它们。
Alkanes are: · 烷烃是:
Alkanes have only single C–C bonds (saturated) and follow CₙH₂ₙ₊₂. · 烷烃只有单 C–C 键(饱和),遵循 CₙH₂ₙ₊₂。
Alkanes are saturated hydrocarbons containing only single bonds. · 烷烃是只含有单键的饱和碳氢化合物。
General formula CₙH₂ₙ₊₂. · 通式 CₙH₂ₙ₊₂。
Making alkanes
- hydrogenation 氢化: add hydrogen to an alkene (Pt or Ni catalyst, heat).
- cracking 裂化: break a long-chain alkane into shorter ones (heat with $\text{Al}_2\text{O}_3$).
An alkene decolourises bromine water; an alkane does not
制造烷烃
- 氢化(hydrogenation):给一个烯烃加氢(Pt 或 Ni 催化剂,加热)。
- 裂解(cracking):把一个长链烷烃断成更短的(用 $\text{Al}_2\text{O}_3$ 加热)。
一个烯烃使溴水褪色;一个烷烃不会
The tetrahedral carbon · 四面体的碳
Each carbon in an alkane has four bonding pairs and no lone pairs — they spread as far apart as possible into a tetrahedron (109.5°). · 烷烃中每个碳有四对成键电子、没有孤对电子——它们尽量分开,形成四面体(109.5°)。
Cracking is used to: · 裂解用于:
Cracking turns heavy crude-oil fractions into smaller, more useful alkanes and alkenes. · 裂解把重的原油馏分变成更小、更有用的烷烃和烯烃。
Match each alkane fact. · 匹配每个烷烃事实。
Each item links the term to its correct meaning. · 每一项把术语链接到它正确的含义。
Combustion 燃烧
- complete (plenty of oxygen) → carbon dioxide + water.
- incomplete (not enough oxygen) → water + toxic carbon monoxide 一氧化碳 (CO) + soot.
Natural gas (mainly methane, an alkane) burns on a stove
燃烧
- 完全(大量氧)→ 二氧化碳 + 水。
- 不完全(氧不够)→ 水 + 有毒的一氧化碳(CO)+ 烟灰。
天然气(主要是甲烷,一种烷烃)在炉子上燃烧
Incomplete combustion of an alkane (not enough oxygen) produces: · 一个烷烃的不完全燃烧(氧不够)产生:
With too little oxygen you get CO (toxic) and carbon (soot) as well as water. · 氧太少时,你得到 CO(有毒)和碳(烟灰)以及水。
Unreactivity and environment
- Alkanes are unreactive towards polar reagents: the C–H and C–C bonds are strong and have little polarity, so there's no charge to attract attack.
- Burning them in engines gives CO, NOₓ and unburnt hydrocarbons — a catalytic converter removes these.
不活泼性和环境
- 烷烃对极性试剂不活泼:C–H 和 C–C 键强且极性很小,所以没有电荷吸引进攻。
- 在发动机中燃烧它们给出 CO、NOₓ 和未燃烧的碳氢化合物——一个催化转化器移除这些。
Alkanes are unreactive towards polar reagents because their bonds are: · 烷烃对极性试剂不活泼,因为它们的键是:
Non-polar, strong C–H and C–C bonds give no charged site for an attacking species. · 非极性、强的 C–H 和 C–C 键不给进攻物种带电的位点。
You've got it
- alkanes = saturated hydrocarbons ($\text{C}_n\text{H}_{2n+2}$); made by hydrogenation or cracking
- complete combustion → CO₂ + water; incomplete → toxic CO + soot
- unreactive (strong, non-polar bonds); engine pollutants removed by a catalytic converter
你掌握了
- 烷烃 = 饱和碳氢化合物($\text{C}_n\text{H}_{2n+2}$);由氢化或裂解制造
- 完全燃烧 → CO₂ + 水;不完全 → 有毒的 CO + 烟灰
- 不活泼(强的、非极性键);发动机污染物由一个催化转化器移除