Question

Which one of the following is not present in the nitration mixture?

• A. $\overset{+}NO_2$
• B. $HSO_4^{-}$
• C. $SO^{2-}_4$
• D. $H_2O$

Answer 1

Answer: (C)

$SO^{2-}_4$

Answer 2

Nitration mixture contains equimolar ratio (i.e. $1: 1)$ of nitric acid and sulphuric acid. It contains $\underset{+}{N}O _{2}, HSO _{4}^{-}$ and $H _{2} O$ species. It does not contain $SO _{4}^{2-}$ ions. This can be explained on the basis of generation of nitronium $\overset{+}{N}O _{2}$ ion from nitrating mixture. Generation of $\overset{+}{N}O _{2}$ ion Step 1 Step II $H - \overset{\underset{|}{H}}{O^+} - NO_2 {<=>} \overset{+}{N}O_2 + H_2O$