What is Benzene?

Benzene is a liquid chemical that has a characteristic of sweet smell and has no color. It is naturally present in crude oil although it can be synthesized from petroleum products. Benzene is classified as an aromatic hydrocarbon due to the more sequential bond between carbon atoms, which is usually cyclic. Benzene has been found to be a valuable precursor in the production of many materials including but not limited to drugs, dyes, lubricants, rubbers, detergents, pesticides, explosives and plastics among many other materials.

Chronology

Many scientists have ventured into the study of benzene. Some of them are Linus Pauling and Michael Faraday. In 1825, Faraday announced that he had been isolated from diesel. He called it hydrogen bicarbonate. In 1833, distilling the benzoic acid, Eilhard Mitscherlich was able to produce benzene. Twelve years later, Charles Mansfield isolated benzene from coal tar. He later began producing benzene using the coal-scale procedure on an industrial scale for the first time in 1849. In 1997, benzene was discovered in space. The empirical formula of benzene has been known for a long time. However, it has proved a daunting task to determine its polyunsaturated structure. A German chemist Friedrich August Kekule published an article which shows that the structure of benzene had six carbon atoms that had alternating double and single bonds. He suggested that benzene had a ring structure. He used the evidence that had been collected over the years to defend his proposed structure.

Structure

The chemical formula of benzene is C6H6 and has a ring structure. The carbon bonds (CC) are the same length (140 pm). This length is longer than the length of a double bond (134 pm) and shorter than a single bond (147 pm). Electronic delocalization can explain its characteristic of being intermediary in length. This delocalization is called “aromaticity”. Useful chemicals derive from benzene by replacing a hydrogen atom (s) with a functional group.

Production

Before the Second World War, benzene was primarily a by-product of coke production within the steel industry. Starting in the 1950s, benzene comes mainly from the oil industry due to its enormous demand. There are four primary chemical processes used to produce industrial benzene, and include the hydrodealkylation of toluene, catalytic reforming, steam cracking and the disproportion of toluene. Between 1978 and 1981, the primary process of benzene production in the United States was catalytic reforming, which accounts for about 44-50% of the total benzene production in the country.

it is used

Benzene was used as an aftershave lotion between the 19th and 20th centuries. It has also been used as an industrial solvent. Over time, its toxic nature was obvious. Ludwig Roselius popularized the use of Benzene for coffee decaffeination. As a result, ‘Sanka’ was produced. Before 1950, benzene was used as a gasoline additive. It has reduced engine shocks. Nowadays, benzene is used in the production of other chemicals as an intermediate product. Benzene derivatives include (1) styrene, in the production of plastics and polymers; (2) phenol, which is used for the production of adhesives and resins; and (3) cyclohexane, which is used in the production of nylon.

Health effects

Benzene is known to increase the risk of cancer. Causes bone marrow failure. Benzene has also been associated with aplastic anemia, cardiovascular disease and acute leukemia. According to the American Petroleum Institute of 1948, the only safe benzene concentration is zero (0).

 

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