# Is ammonium ion a radical?

Mar 16, 2017

$\text{Ammonium ion}$ is not a radical species............

#### Explanation:

The ammonia molecule, $: N {H}_{3}$ is conceived to have a lone pair of electrons localized on the nitrogen centre.

In aqueous solution, this lone pair is conceived to donate to an hydrogen ion in an acid base reaction as shown:

$N {H}_{3} \left(a q\right) + {H}_{2} O \left(l\right) r i g h t \le f t h a r p \infty n s N {H}_{4}^{+} + H {O}^{-}$

All chemical reactions conserve charge. Has charge been conserved here?

Certainly, we can measure the extent of this equilibrium reaction (conveniently by measuring the $p H$ of the solution:)

${K}_{\text{eq}} = \frac{\left[N {H}_{4}^{+}\right] \left[H {O}^{-}\right]}{\left[N {H}_{3}\right]} = {10}^{- 4.75} = 1.78 \times {10}^{-} 5$.

In ammonium cation, there are SIX electrons associated with nitrogen, rather than the 7 required for neutrality. The nitrogen in ammonia is (so-called) quaternized, and thus bears a positive charge. Certainly, we can use ammonium salts such as $N {H}_{4} C l$, and ${\left(N {H}_{4}\right)}_{2} S {O}_{4}$ in the lab.

$\text{Ammonium nitrate}$, when mixed with fuel oil, is a potent high explosive.