苯与汽油
Benzene
Benzene only has carbon and hydrogen atoms arranged to give a planar structure. It has the molecular formula of C6H6。它的结构及其某些属性如下。
分子量：78 g摩尔-1
沸点：80.1oC
Melting point: 5.5oC
密度：0.8765 g cm-3
苯是一种无色液体，具有甜味。它是易燃的，并在暴露时会迅速蒸发。苯可以用作溶剂，因为它可以溶解许多非极性化合物。但是，苯略有溶于水。与其他脂肪族烃相比，苯的结构是独一无二的。因此，苯具有独特的特性。苯所有碳均有三个SP2杂交轨道。两个sp2碳与SP重叠的杂交轨道2两侧相邻碳的杂交轨道。其他sp2杂化轨道与s轨道的重叠hydrogen to form a σ bond. The electrons in p orbitals of a carbon overlap with the p electrons of carbon atoms in both sides forming pi bonds. This overlap of electrons happens in all the six carbon atoms and, therefore, produces a system of pi bonds, which are spread over the whole carbon ring. Thus, these electrons are said to be delocalized. The delocalization of the electrons means that there aren’t alternating double and single bonds. So all the C-C bond lengths are the same, and the length is between single and double bond lengths. Because of the delocalization, the benzene ring is stable; it is reluctant to undergo addition reactions, unlike other alkenes.
Gasoline
汽油是大量碳氢化合物的混合物，这些烃具有5-12碳。有脂肪族烷烃，例如七烷，等烷烃，例如等辛烷，脂肪族环状化合物和小芳香族化合物。但是，除了这些碳氢化合物外，没有其他烯烃或炔烃。汽油是石油行业的天然副产品，它是不可再生的来源。在原油的分数蒸馏中生产汽油。当它们根据其沸点分离时，在同一范围内收集了汽油中的低分子加权化合物。汽油有时在某些国家（也称为汽油），这是用于车辆内燃机的燃料。汽油的燃烧会产生大量的热能以及二氧化碳和水。其他化合物与汽油混合在一起，以增强其在发动机中的使用。等辛烷或苯和甲苯等碳氢化合物被添加到汽油中，以增加其辛烷值。 This octane number measures the ability of an engine to cause self ignition in the engine cylinders (which causes knocking). When gasoline and air mixture are caught in premature ignition, before the spark is passed from the spark plug, it pushes against the crankshaft producing a knocking sound. Due to knocking the engine tends to overheat and loose power. Therefore, it damages the engine in the long run. So to reduce this octane number of the fuel has to be increased. Other than adding hydrocarbons stated above, the octane number can also be increased by adding certain lead compounds. This will increase the octane number; thus, gasoline will be more resistant to self ignition, which causes knocking. Gasoline prices are largely varying over time with the price of crude oil. Since gasoline has become a primary need in most of the countries, the variation in oil prices affects the country’s economy too.
有什么区别Benzene and Gasoline？ •苯是一种烃分子，汽油是烃的混合物。 •汽油含有带有苯环的烃。 •自然，苯存在于汽油等石化物中。 • Benzene is added to gasoline, to increase its octane rating. |
发表评论