Question

What is carbonisation of coal in production of coal tar?
A) Heating of coal in absence of air
B) Heating of coal in excess of air
C) Heating of coal while adding carbon
D) Both B and C

Answer 1

We need to know that the Coal tar is a mixture of various substances. Coal tar has some hydrocarbon molecules like alkane, alkene, alkyne and benzene related molecules. It also has some alcohol derived compounds also. Phenol is one of the mono substituent benzene compounds. Each mono-substituted moiety has three named positions in the ring. In the ring a nearby mono substituent group is called ortho position, that means two ortho positions are in the ring, because of the left and right side of the substituent group. The alternatively position of the substituent group in the ring is called meta position, here also two meta positions possible in the left and right side of the substituent group. Para position is nothing but directly opposite to the substituent group in the ring. Electrophilic substitutions are attacked in ortho and para position in the ring.

Complete answer:
We have to remember that carbonisation of coal is nothing but the production of coal tar by heating in absence of air and should maintain higher temperature here coal is the key raw material.
According to the above discussion carbonisation of coal in production of coal tar by heating of coal in absence of air.

Hence, option A is the correct answer.

Note:
As we know that in organic chemistry, hydrocarbons are an important topic. The hydrocarbons are majorly classified as three groups. There are alkane, alkene and alkyne. The alkane means carbon-carbon single bond. The alkene has a carbon-carbon double bond. The alkyne means carbon-carbon having triple bond in the molecule. It has some general formulas. The general formula of alkane is ${{\text{C}}_{\text{n}}}{{\text{H}}_{{\text{2n + 2}}}}$. The general formula of alkene is ${{\text{C}}_{\text{n}}}{{\text{H}}_{{\text{2n}}}}$. The general formula of alkyne is ${{\text{C}}_{\text{n}}}{{\text{H}}_{{\text{2n - 2}}}}$. Coal tar is a mixture of various substances. Coal tar has some hydrocarbon molecules like alkane, alkene, alkyne and benzene related molecules. It also has some alcohol derived compounds also. The conversion of one type of hydrocarbon to other hydrocarbon by oxidation and reduction. The oxidation of alkane to give alkene. The oxidation of alkene to give alkyne. The reduction of alkyne to give alkene. The reduction of alkene to give alkane. The oxidation means the addition of oxygen or removal of hydrogen or the loss of electrons in the reactant in chemical reaction. The reduction means the removal of hydrogen or the addition of oxygen or the gain of electrons in the chemical reaction.