Question

A compound is soluble in conc. $H_{2}S{O}_4$. It does not decolourise bromine in carbon tetrachloride but is oxidised by chromic anhydride in aqueous sulphuric acid within two seconds, turning orange solution to blue, green and then opaque. The original compound is

• A. a primary alcohol
• B. a tertiary alcohol
• C. an alkane
• D. an ether

Answer 1

Answer: (A)

Solubility of the compound in cone. $H_{2}S{O}_4$ indicates that it can be an alkene, alcohol or an ether. The inability to discharge bromine colour indicates absence of an alkene. Hence the compound is an alcohol which should be primary because it is readily (within $2$ seconds) oxidised by $Cr{O}_3$ in sulphuric acid.