辛烷值公式 – 结构、性质、用途、示例问题
辛烷是由碳和氢原子组成的碳氢化合物。辛烷的分子式是 C 8 H 18 。大多数烃基存在于石油中。辛烷具有许多结构异构体,但它们根据碳链中支链的数量和位置而有所不同。它存在于原油中,由 Edwin L. Drake 于 1859 年 8 月发现。
碳
碳是一种化学元素,符号是C。它的原子序数是6。碳的电子结构是1s 2 2s 2 2p 2 有四个价电子。这是一个重要的元素,因为它在现实生活中起着非常重要的作用。碳存在于所有生物结构中。它的化合物在现实生活中随处可见,例如:疼痛、药物、塑料、棉花、羊毛、煤炭等。
氢
氢是一种化学元素,用符号H表示,其原子序数为1。这种元素是亨利·卡文迪什在1766年发现的。自然,氢以分子形式存在,它是地球上最丰富的元素。它是最轻的元素,可用于燃料电池发电。氢对于生命来说是必不可少的,如果没有这种元素,我们就没有太阳给我们光和热。它有氢、氘、氚三种同位素。
辛烷值
辛烷是一种烃和烷烃,化学式为 C 8 H 18 。它是一种存在于汽油或汽油中的化学物质,用于测量燃料的质量。无色液体,有汽油味,易挥发,极易燃的无色液体。其额定值是通过燃料避免爆震的能力来衡量的,当燃料在发动机气缸中永久点燃时会发生爆震,这会降低效率并可能损坏发动机,燃料中含有一种含氧化合物,可通过向燃料中添加氧气来防止爆震,这种含氧化合物通常称为辛烷值。
辛烷的结构
辛烷的缩合结构式为 CH 3 (CH 2 ) 6 CH 3 。
物理性质
- 它的摩尔重量为 114.23 g/mol
- 它的沸点是125.6°C
- 辛烷的熔点是-57°C
- 其密度为 703 kg/m 3
- 它是一种高度易燃的无色液体。
- 它是一种无色液体,有汽油味
化学性质
碳氢化合物在自然界中以多种形式存在,主要以液态石油的形式存在,它被称为原油以将其与精炼油区分开来,它是最重要的商业天然气,是碳氢化合物的较轻馏分,可以是游离或溶解的沥青、焦油、沥青是固体或半固体形式的烃类重质馏分。
辛烷的用途
- 它用作溶剂。
- 它被用作化学原料。
- 在石油工业中用作重要的化学试剂。
- 它被用作汽油的成分。
- 辛烷值用于确定燃料的质量。
示例问题
问题 1:辛烷中有多少种异构体?
回答:
Octane has 18 isomers. They are Octane, 2-Hethylheptane, 3-Hethylheptane, 4-Hethylheptane, 2,2-Dimethylhexane, 2,3-Dimethylhexane, 2,4-Dimethylhexane, 2,5-Dimethylhexane, 3,3-Dimethylhexane, 3,4-Dimethylhexane, 3-Ethylhexane, 2,2,3-Trimethylpentane, 2,2,4-Trimethylpentane, 2,3,3-Trimethylpentane, 2,2,4-Trimethylpentane, 2-Methyl-3-etylpentane, 3-Methyl-3-etylpentane, Tetramethylbutane, 15 of them are positional isomers and 3 of them stereoisomers.
These isomers are differed by the amount and location of branching in the carbon chain.
问题 2: 哪种化合物用于计算十六烷值?
回答:
The cetane molecule is used to calculate the cetane number its formula is C16H34. It is a saturated hydrocarbon and has a very short ignition lag as compared to any commercial deiseal fuel. Its cetane number is 100. Cetane Number is the percentile of cetane in a mixture of cetane and α-methyl naphthalene.
问题 3:哪一种用于降低脱密封燃料的表面张力?
回答:
The chemical addictive’s are used to reduce the surface tension thus promoting the formation of finer spray .inhibitors are used to delay or prevent gum formation and poly hydrocarbons are used to preserve the fluid properties.
问题4:用什么化合物来计算辛烷值?
回答:
An octane number is a number that is used to determine the quality of petrol fuel. Two pure hydrocarbons have been selected slandered by edger
- n-heptane
- Iso-octane
The octane number of iso-octane is 100 and the octane number of n-heptane is 0. The octane number of a fuel is numerically taken as the percentage of iso-octane in a mixture of iso-octane and n-heptane.
问题5:辛烷的摩尔质量是多少?如何计算?
回答:
The molar mass of octane is 114.23 g/mol. The carbon atomic mass is 12.0107. The number of atoms in carbon is 8. The atomic mass of hydrogen is 1.00794. The number of atoms in hydrogen is 18.
Finally, molecular mass calculation is = 12.0107 × 8 + 1.00794 × 18
= 96.0856 + 18.14292
= 114.22852
问题 6:辛烷是什么类型的键?
回答:
Octane belongs to a family of molecules called alkanes. These are hydrocarbons molecules with just single, two-electron bonds connecting the atoms. There is a whole series of them with increasing numbers of carbon atoms.
Examples of alkanes are methane, ethane, propane, etc.
问题7:什么是敲门?
回答:
It is a sharp rattling sound produced in the internal combustion engine due to immature ignition of the air gasoline mixture the pressure of some constituents in the gasoline used causes the rate of oxidation to become so great that a lost portion of the fuel-air mixture gets ignited instantaneously producing explosive violence its called Knocking.