Lawrie Ryan and Roger Norris Solutions for Chapter: Benzene and its Compounds, Exercise 5: Question

Copy and complete the equation below, which can be used to show the nitration of methylbenzene:

${\mathrm{C}}_6{\mathrm{H}}_5{\mathrm{CH}}_3+{\mathrm{NO}}_2^{+}\to \mathrm{\_\_\_\_\_}+\mathrm{\_\_\_\_\_}.$

Copy and complete the equation below, which can be used to show the nitration of methylbenzene:

${\mathrm{C}}_6{\mathrm{H}}_5{\mathrm{CH}}_3+{\mathrm{HNO}}_3\stackrel{{\mathrm{H}}_2{\mathrm{SO}}_4}{\to }\mathrm{\_\_\_\_\_}+\mathrm{\_\_\_\_\_}.$

Copy and complete the two equations below, which can both be used to show the nitration of methylbenzene:

i. ${\mathrm{C}}_6{\mathrm{H}}_5{\mathrm{CH}}_3+{\mathrm{NO}}_2^{+}\to \mathrm{\_\_\_\_\_}+\mathrm{\_\_\_\_\_}.$

ii. ${\mathrm{C}}_6{\mathrm{H}}_5{\mathrm{CH}}_3+{\mathrm{HNO}}_3\stackrel{{\mathrm{H}}_2{\mathrm{SO}}_4}{\to }\mathrm{\_\_\_\_\_}+\mathrm{\_\_\_\_\_}.$

Name the possible mono-substituted products in parts i and ii.

$2,4$-dinitromethylbenzene and $2,4,6$-trinitromethylbenzene are formed on further nitration of methylbenzene. Draw the displayed formula of each compound.

Benzene also undergoes electrophilic substitution when refluxed with fuming sulphuric acid for several hours. This is called sulphonation. The electrophile is the ${\mathrm{SO}}_3$ molecule and the product formed is benzenesulphonic acid, ${\mathrm{C}}_6{\mathrm{H}}_5{\mathrm{SO}}_3\mathrm{H}$. Suggest which atom in the ${\mathrm{SO}}_3$ molecule accepts an electron pair in the mechanism of sulphonation.

Benzene also undergoes electrophilic substitution when refluxed with fuming sulphuric acid for several hours. This is called sulphonation. The electrophile is the ${\mathrm{SO}}_3$ molecule and the product formed is benzenesulphonic acid, ${\mathrm{C}}_6{\mathrm{H}}_5{\mathrm{SO}}_3\mathrm{H}$. Write an equation in the style of ${\mathrm{SO}}_3$ molecule accepts an electron pair in the mechanism of sulphonation of benzene to form benzenesulphonic acid.