章节大纲

  • A technician using an oxy-acetylene torch to cut metal, sparks flying.

    What's better than a hacksaw?
    ::有什么比黑锯更好的?

    One of the most effective ways to cut metal is with an oxy-acetylene torch. Very high temperatures are obtained when acetylene burns in oxygen. Mixed 1:1 with oxygen, a temperature of over 3000°C can be achieved. The amount of energy released is high – the net is 1300 kJ/ mole . Safety precautions need to be observed since the is very explosive. For welding and cutting, the oxy-acetylene torch is one of the best ways to go.
    ::切除金属的最有效方法之一是用氧乙炔火炬切割金属。当氧气中乙炔燃烧时,将获得极高的温度。 混合1:1与氧气,可达到3000°C的温度。 释放的能量量很高 — — 净值为1300千焦耳/摩尔。 安全预防措施需要观察,因为爆炸性很强。 对于焊接和切割,氧乙炔火炬是最好的方法之一。

    Alkenes and Alkynes
    ::阿尔肯内斯和阿尔基内斯

    Alkenes
    ::代数

    An alkene is a with one or more carbon-carbon double covalent bonds . The simplest alkene is composed of two carbon atoms and is called ethene (shown below). Each carbon is bonded to two hydrogen atoms in addition to the double bond between them.
    ::烷是一种具有一个或多个碳-碳双倍共价债券的烷。 最简单的烷由两个碳原子组成,称为乙烯(如下表所示 ) 。 每种碳除了两个碳之间的双倍债券之外,还被绑在两个氢原子上。

    Chemical structure of ethene, illustrating carbon-carbon double bond and hydrogen atoms.

    The hybridization of each carbon is sp 2 with trigonal planar geometry. All the atoms of the molecule lay in one plane. Like the alkane series, the names of alkenes are based on the number of atoms in the parent chain. Naming follows the same rules as for alkanes, with the addition of using a number to indicate the location of the double bond. Propene (C 3 H 6 ) has three carbons total, while butene (C 4 H 8 ) has four. The general formula for alkenes with one double bond is C n H 2n . Alkenes are called . An unsaturated hydrocarbon is a hydrocarbon that contains less than the maximum number of hydrogen atoms that can possibly bond with the number of carbon atoms present.
    ::每种碳的混合化为 sp2 和 三角平面平面几何。 分子的所有原子都位于一平面上。 和 烷系列一样, 藻类的名称以母链中的原子数量为基础。 命名遵循与 alkane 相同的规则, 并加上一个数字来表示双倍保证金的位置。 Propene (C3H6) 共有三颗碳, 而 butene (C4H8) 共有四颗。 双倍保证金的藻类一般公式是 CnH2n。 阿尔肯斯被称作。 不饱和碳氢化合物是一种碳氢化合物, 其含量小于氢原子的最大数量, 可能与存在的碳原子数量挂钩 。

    The location of the carbon-carbon double bond can vary. The 4-carbon alkene generic name is butene. Since the double bond can be located in more than one place, we have 1-butene and 2-butene:
    ::碳-碳双份保证金的位置可能不同。 4- 碳- 烷通用名称为丁烯。 由于双份保证金可以位于不止一个地方,我们有1- 丁烯和2- 丁烯:

    Chemical structure of 1,3-butadiene showing double bonds between carbon atoms.

    Molecules with multiple double bonds are also quite common. The formula below shows a four-carbon chain with double bonds between carbons 1 and 2 and between carbons 3 and 4. This molecule is called 1,3-butadiene.
    ::多双倍债券的分子也很常见。 以下公式显示了碳1和2之间以及碳3和4之间的双倍债券的四碳链。 这个分子被称为1,3-丁二烯。

    Chemical structure of 1,3-butadiene, a four-carbon chain with two double bonds.

    Alkynes
    ::ALkynes

    An alkyne is a hydrocarbon with one or more carbon-carbon triple . The simplest alkyne consists of two carbon atoms and is called ethyne (common name: acetylene).
    ::Anlkyne是一种碳氢化合物,一种或多种碳碳三联。最简单的烷由两个碳原子组成,称为ethyne(共同名称:乙炔)。

    Structural representation of the ethyne molecule, showing its linear configuration and carbon bonds.

    The ethyne molecule is linear, with sp hybridization for each carbon atom. The general formula of alkynes with one triple bond is C n H 2n-2 . Alkynes are also unsaturated hydrocarbons. Other alkynes exist, such as 2-pentyne:
    ::苯乙烯分子是线性分子,每个碳原子都有螺旋混合作用。一个三联环的alkynes一般配方为CnH2n-2。Alkyne也是不饱和的碳氢化合物。

    Structural representation of the 2-pentyne molecule, showcasing its linear shape and triple bond.

     

     

     

    Review
    ::回顾

    1. What is an alkene?
      ::什么是白银?
    2. What is an alkyne?
      ::什么是烷基?
    3. Can a compound have more than one carbon-carbon double bond in it?
      ::复方能有一个以上的碳碳双倍债券吗?