Question

How is Nitronium Ion formed from Nitrating Mixture?

Answer 1

The formation of Nitronium ion from nitrating mixture:

• The nitrating mixture is the combination of concentrated Sulphuric acid and Nitric acid $({\mathrm{H}}_2\mathrm{S}{\mathrm{O}}_4+\mathrm{HN}{\mathrm{O}}_3)$. The Nitric acid accept proton from Sulphuric acid and form Nitrooxonium and Sulphate ion.
• In an electrophilic substitution reaction, the formation of Nitronium ion takes place. The Nitronium ion has a positive charge on the Nitrogen atom $\mathrm{N}{{\mathrm{O}}_2}^{+}$.
• The mechanism shows the formation of Nitronium ion.

Step1: The formation of nitrooxonium and sulphonate ion takes place.

$\mathrm{Nitic}\mathrm{acid}$ $\mathrm{Sulphuric}\mathrm{acid}$ $\mathrm{Nitrooxonium}$ $\mathrm{Sulphonate}\mathrm{ion}$

Step 2: The nitrooxonium releases water and the formation of $\mathrm{N}{{\mathrm{O}}_2}^{+}$takes place.

$\mathrm{Nitrooxonium}$ $\mathrm{Nitronium}\mathrm{ion}$ $\mathrm{water}$

Thus, the Nitronium ion can be separated from the Nitrating mixture.