alevel化学总分如何计算(alevel化学考试题型)

有机化学部分的知识点散而多,有很多的概念需要理解和记忆,今天小编为大家总结了ALevel化学考试中烷烃部分(Alkane)需要掌握的几个概念,下面就一起来学习一下吧!

  适用于各大考试局:Edexcel,CAIE,AQA等等

  以CAIE ALevel Chemistry考试大纲为例,来看对Alkane的考察要求:

  a) understand the general unreactivity of alkanes, including towards polar reagents

  b) describe the chemistry of alkanes as exemplified by the following reactions of ethane:

  (i) combustion

  (ii) substitution by chlorine and by bromine

  c) describe the mechanism of free-radical substitution at methyl groups with particular reference to the initiation, propagation and termination reactions

  d) explain the use of crude oil as a source of both aliphatic and aromatic hydrocarbons

  e) suggest how cracking can be used to obtain more useful alkanes and alkenes of lower Mr from larger hydrocarbon molecules

  几个重要的概念总结如下:

  1

  Catalytic converter

  A device fitted in a car to reduce the amount of emissions from an internal combustion engine. They use expensive metals like platinum and rhodium as the heterogeneous catalyst. The catalyst is mounted on a ceramic honeycomb to maximise the surface area.

  2

  Catalytic cracking

  A type of cracking that takes place at a slight pressure, high temperature and in the presence of a zeolite catalyst and is used mainly to produce motor fuels and aromatic hydrocarbons.

alevel考试题型

  3

  Combustion of alkanes

  Combustion of alkanes releases energy.

  During combustion, the carbon and hydrogen in the fuels are oxidised. Alkanes can undergo complete or incomplete combustion. Water and carbon dioxide are the only products of the complete combustion, whereas carbon monoxide and carbon particulates can be produced in incomplete combustion.

  4

  Cracking

  A process which involves breaking C-C bonds in alkanes to produce shorter chained alkanes and alkenes.

  5

  Crude oil

  A finite resource found in rocks. It is the remains of an ancient biomass consisting mainly of plankton that was buried in mud. Most of the compounds in crude oil are hydrocarbons.

  6

  Fractional distillation

  A method of separating a mixture of substances according to their different boiling points. Commonly used to separate crude oil into different fractions.

  7

  Hydrocarbons

  Compounds made up of carbon and hydrogen atoms only.

  8

  Saturated

  Organic compounds are saturated if all the carbon-carbon bonds are single C-C bonds. Alkanes are saturated hydrocarbons.

  9

  Thermal cracking

  A type of cracking that takes place at high pressure and high temperature and produces a high percentage of alkenes.

  以上就是小编为大家带来的ALevel化学考试中烷烃需要掌握的概念,希望考生们在备考中重视起来,除此之外,大家也要在平时多多积累词汇,打好备考技巧的基础。如果想要获取更多alevel考试题型、alevel网络课程等更多信息,大家可以线上咨询我们或继续关注网站更新的文章!

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