Question
A compound $$(A)$$ of molecular formula $${C_7}{H_8}O$$ is insoluble in water and dilute sodium bicarbonate but dissolves in dilute aqueous sodium hydroxide and gives a characteristic colour with aqueous $$FeC{l_3}.$$ On treatment with bromine water, it readily gives a precipitate of $${C_7}{H_5}OB{r_3}.$$ Write down the structure of the compound $$(A).$$
A.
B.
C.
D.
Answer :
Solution :
(i) Since $$A$$ gives characteristic colour with aqueous $$FeC{l_3}$$ so it contains a phenolic group.
(ii) Since $$A$$ when treated with $$B{r_2}$$ forms $${C_7}{H_5}OB{r_3}$$ (ppt.) and considering the molecular formula of $$A,$$ it is most likely to be cresol.
(iii) Since $$A$$ on bromination forms tribromo derivative so, it is $$m$$ - cresol i.e..PNG "Alcohol, Phenol and Ether mcq solution image")
The reactions are :
.PNG "Alcohol, Phenol and Ether mcq solution image")
(i) Since $$A$$ gives characteristic colour with aqueous $$FeC{l_3}$$ so it contains a phenolic group.
(ii) Since $$A$$ when treated with $$B{r_2}$$ forms $${C_7}{H_5}OB{r_3}$$ (ppt.) and considering the molecular formula of $$A,$$ it is most likely to be cresol.
(iii) Since $$A$$ on bromination forms tribromo derivative so, it is $$m$$ - cresol i.e.
The reactions are :