Question

The coal tar fraction which contains phenol is:
A) Middle oil
B) Green oil
C) Heavy oil
D) Light oil

Answer 1

Hint: Coal tar is a by-product generated by the coke. The second fraction of coal-tar distillation which distills at 170$^\circ$-230$^\circ$C is called middle oil.

Complete answer:
Coal tars are carbonization by-products of coal generating coke and/or natural gas.
Coal tars, the dark, viscous, often semi-solid, odor fluid mixed with aqueous "gas liquor" when the volatile products of the destructive coal distillation are cooled down. It is also called "gas-tar," because it was previously exclusively, and even now mostly, obtained as a by-product in the production of coal-gas, but the tar obtained from the modern coke-ovens, although not entirely identical to gas-tar, resembles it to such an extent that it is worked up with the latter, without making any distinction in practice between the two types.
Physically they are typically viscous liquids or semi-solids that are black or dark brown with an odor similar to naphthalene.
Medium oil is the part of the distillate obtained from carbon tar that passes between \[170^\circ \] and \[230^\circ \,{\text{C}}\].
By distilling coal tar, green oil (anthracene oil) is obtained at \[270^\circ - 360^\circ \,{\text{C}}\]. It contains primarily anthracene and phenanthrene.
Light oil, made up of hydrocarbons, mainly benzene homologues, along with phenol and pyridine, amounts to \[7 - 8\,{\text{% }}\] of tar.
Coal tars are complex combinations of polycyclic aromatic compounds such as hydrocarbons, phenols, heterocyclic oxygen, sulphur and nitrogen.
By contrast, charcoal tar creosotes are coal tar distillation products. They are sticky in liquid consistency and range from yellowish-dark green to brown in color.
The coal tar creosotes are derivatives of aromatic hydrocarbons, anthracene, naphthalene and phenanthrene.

Hence, the answer is (A).

Note: Coal is a mixture of many compounds which are very sticky in nature. Coal tar is obtained by cooling the gas that is formed during the distributive distillation of coal.