Question

Absolute alcohols (100% ethanol) are prepared from rectified spirit (95% ethanol) by mixing a suitable amount of ............... and subjected to fractional distillation (azeotropic distillation).
a.) Toluene
b.) o – Xylene
c.) Methanol
d.) Benzene

Answer 1

Hint: Absolute alcohol (also called ethanol) is a chemical compound, a basic alcohol with the formula \[{C_2}{H_6}O\] in chemical form. The formula can also be written as \[{C_2}{H_5}OH\].
Complete step-by-step answer:
Ethanol is a liquid that is volatile, flammable, colorless and has a slight odor. This is a psychoactive drug, which is the primary active ingredient in alcoholic drinks.
Absolute alcohol is 100% ethanol that is prepared with rectified spirit. Absolute alcohol is prepared by method of Azeotropic distillation. Rectified spirit is combined with a sufficient volume of benzene and diluted fractionally.
Hence option D is the right answer.

Note: An organic chemical compound Benzene has molecular formula \[{C_6}{H_6}\]. The benzene molecule consists of six carbon atoms which are joined together in a planar ring with one hydrogen atom connected to each. Benzene is known as hydrocarbon, since it contains only atoms of carbon and hydrogen. Benzene is a natural component of crude oil, which is one of the essential petrochemicals. Benzene is known as an aromatic hydrocarbon because of the cyclic continuous pi bonds between the carbon atoms, the second [n]-annulene. PhH is sometimes abbreviated. Benzene is a colorless, highly flammable, sweet-smelling substance that is responsible for the fragrance around fuel stations. This is mainly used as a precursor to the manufacture of chemicals that have a more complex structure, such as ethyl benzene and cumene, which generate billions of kilograms annually. Since benzene has a high number of octanes, aromatic derivatives such as toluene and xylene usually compose up to 25 per cent of petrol. Benzene itself was limited in gasoline to less than 1 per cent because it is a recognized human cancer. For the same purpose, most non-industrial applications were restricted too.