Ammonium nitrate NH4NO3 consists of two ions: the ammonium ion NH4+ and the nitrate ion NO3- . To find the oxidation state of nitrogen in ammonium nitrate, we need to determine the oxidation state of nitrogen in each ion separately.1. In the ammonium ion NH4+ , nitrogen is bonded to four hydrogen atoms. Hydrogen has an oxidation state of +1. Therefore, the oxidation state of nitrogen in the ammonium ion is -3 since +1 * 4 = +4, and nitrogen's oxidation state must balance the charge: -3 + 4 = +1 .2. In the nitrate ion NO3- , nitrogen is bonded to three oxygen atoms. Oxygen has an oxidation state of -2. Therefore, the oxidation state of nitrogen in the nitrate ion is +5 since -2 * 3 = -6, and nitrogen's oxidation state must balance the charge: +5 - 6 = -1 .So, in ammonium nitrate NH4NO3 , nitrogen has two different oxidation states: -3 in the ammonium ion and +5 in the nitrate ion.