What is the oxidation state of nitrogen in hydroxylamine?

1 Answer
Nov 26, 2015

Answer:

The oxidation number of #N# in hydroxylamine, #H_2N-OH#, is #-I#.

Explanation:

By definition, the oxidation number of any atom in a molecule, is the charge left on that atom, when all the bonding pairs of electrons are conceptually broken, with the charge going to the most electronegative atom. Break a #N-H# bond and we get #N^-# and #H^+#. Break a #N-OH# bond and we get #N^+#, and #HO^-#, because oxygen is more electronegative than nitrogen, the oxygen centre gets the electron (please note that this is entirely a conceptual exercise!).

The sum of the individual oxidation numbers must equal the charge on the molecule or the ion. Here, we have a neutral molecule. So #3xxON_H+ ON_O + ON_N# #=# #0#; so #3xx1-2+ON_N = 0#. Thus #ON_N=-I#.

Can you hazard a guess (or a reasoned answer) as to the formal oxidation numbers of nitrogen in ammonia, #NH_3#, and in hydrazine, #H_2N-NH_2#?