关键差异 -烷烃vs Alkenes
烷烃和烷烃是两种类型的烃家族，它们的分子结构中含有碳和氢。烷烃和烷烃之间的主要区别在于它们的化学结构。alkanes are saturated hydrocarbons with the general molecular formula of CnH2n+2and alkenes are said to be anunsaturated hydrocarbon由于它们包含一个双键between two carbon atoms. They have the general molecular formula of CnH2n.
什么是烷烃？
烷烃contain only single bonds between Carbon and hydrogen atoms (C-C bonds and C-H bonds). Therefore, they are called “saturated hydrocarbons”. According to the orbital hybridization model, all the carbon atoms in Alkenes have the SP3hybridization. They formsigma bonds氢原子和所得分子具有四面体的几何形状。烷烃可以根据它们的分子排列将两组细分为两组。无环烷烃（CnH2n.+2）和环烷烃（CnH2n).
什么是烯烃？
Alkenes are the hydrocarbons, containing a Carbon-Carbon (C=C) double bond.“Olefins”is the old name used to refer to the alkene family. The smallest member of this family is乙烷(C2H4）；它被称为Olefiant gas (In Latin: ‘oleum’means ‘oil’ +‘facere’means ‘to make’) in early days. This is because the reaction between C2H4氯给出C2H2Cl2, oil.
What is the difference between Alkanes and Alkenes?
烷烃和烷烃的化学结构
烷烃:烷烃have the general molecular formula CnH2n+2.甲烷(CH4）是最小的烷烃。
| Name | Chemical formula | Acyclic structure |
| 甲烷 | CH4 | CH4 |
| 乙烷 | C2H6 | CH3CH3 |
| 丙烷 | C3H8 | CH3CH2CH3 |
| Butane | C4H10 | CH3CH2CH2CH3 |
| 戊烷 | C5H12 | CH3CH2CH2CH2CH3 |
| Hexane | C6H14 | CH3CH2CH2CH2CH2CH3 |
| Heptane | C7H16 | CH3CH2CH2CH2CH2CH2CH3 |
| Octane | C8H18 | CH3CH3CH2CH2CH2CH2CH3CH3 |
Alkenes:烯烃具有C的一般化学式nH2n. Alkenes are considered to be unsaturated hydrocarbons since they do not contain the maximum number of Hydrogen atoms that can be owned by a hydrocarbon molecule.
| Name | Chemical formula | 结构 |
| Ethene | C2H4 | CH2 =CH2 |
| Propene | C3H6 | CH3CH = CH2 |
| Butene | C4H8 | CH2=chch2CH3,CH3CH=CHCH3 |
| Pentene | C5H10 | CH2=chch2CH2CH3,CH3CH=CHCH2CH3 |
| Hexene | C6H12 | CH2=chch2CH2CH2CH3CH3CH=CHCH2CH2CH3 CH3CH2CH=chch2CH3 |
| Heptene | C7H14 | CH=chch2CH2CH2CH2CH3CH3CH=CH2CH2CH2CH2CH3 |
Chemical Properties of Alkanes and Alkenes
烷烃:
Reactivity:
烷烃对许多化学试剂惰性。这是因为碳 - 碳（C-C）和碳 - 氢（C-H）键非常强，因为碳和氢原子的键几乎相同electronegativityvalues. Therefore, it is very difficult to break their bonds, unless they are heated to fairly high temperatures.
Combustion:
烷烃很容易在空中燃烧。烷烃与多余的氧气之间的反应称为“燃烧”。在此反应中，烷烃转化为二氧化碳（CO2) and water.
CnH2n+ (n + n/2) O2→ n CO2 +NH2O
C4H10+ 13/2 O2→ 4 CO2+ 5H2O
Butane Oxygen Carbon Dioxide Water
The combustion reactions are放热反应（他们散发热量）。结果，烷烃被用作能源。
Alkenes:
Reactivity:
烯烃在细分金属催化剂存在下与氢反应形成相应的烷烃。没有催化剂的反应速率非常低。
Catalytic hydrogenation is used in food industry to convert liquid vegetable oils to semi-solid fat in making margarine and solid cooking fat.
烷烃和烷烃的物理特性
形式
烷烃:烷烃exist as gases, liquids and solids. Methane, ethane, propane and butane are gases at room temperature. The unbranched structures of hexane, pentane and heptane are liquids. Alkanes which have a higher molecular weight are solids.
CH4到c4H10are gases
C5H12到c17H36are liquids, and
分子量较高的烷烃是软固体
Alkenes:Alkenes show similar physical properties of the corresponding Alkane. Alkenes which have lower molecular weights (C2H4toC4H8) are gases at room temperature and atmospheric pressure. Alkenes having a higher molecular weight are solids.
Solubility:
烷烃:烷烃不溶于水。They are dissolved innon-polaror weakly polar organic solvents.
Alkenes:由于C = C键，烯烃是相对较大的分子。因此，它们可溶于低极性的非极性溶剂或溶剂。水是极性分子，烯烃在水中有点溶于水。
Density:
烷烃:The densities of Alkanes are lower than the density of water. Their density value is nearly 0.7 g mL-1，将水的密度视为1.0 g mL-1.
Alkenes:烯烃的密度低于水的密度。
Boiling points:
烷烃:The boiling point of unbranched alkanes smoothly increases as the number of Carbon atoms and the molecular weight are increasing. In general, branched alkanes have lower boiling points compared to the unbranched alkanes, having the same number of Carbon atoms.
Alkenes: Boiling points are similar to the corresponding alkanes with a small variation.
References: CliffsNotes. (n.d.). Retrieved July 06, 2016, from这里。
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