Is ammonium ion a radical?

Question

Naomi Aronson · Accepted Answer

#"Ammonium ion"# is not a radical species............

The ammonia molecule, #:NH_3# is conceived to have a lone pair of electrons localized on the nitrogen centre. This lone pair is thought to contribute to a hydrogen ion in an acid-base reaction in an aqueous solution, as demonstrated: #NH_3(aq) + H_2O(l) rightleftharpoons NH_4^(+) + HO^-# Is charge conserved here, as it is in all chemical reactions? Of course, we can gauge the magnitude of this equilibrium reaction—conveniently, we can do so by taking the solution's pH reading. #K_"eq"=([NH_4^+][HO^-])/([NH_3])=10^(-4.75)=1.78xx10^-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 #NH_4Cl#, and #(NH_4)_2SO_4# in the lab. #"Ammonium nitrate"#, when mixed with fuel oil, is a potent high explosive.

Olivia Anton · Answer

undefined The ammonium ion is a polyatomic ion with a positive charge that is made up of four hydrogen atoms bound to a central nitrogen atom. Radicals, on the other hand, usually have unpaired electrons; the ammonium ion does not have this property.