The compound consists of two nitrogen atoms: one in the ammonium ion ( ) and one in the nitrate ion ( ).
1. Oxidation state of nitrogen in ammonium ion ( ): The ammonium ion consists of one nitrogen atom and four hydrogen atoms. The oxidation state of hydrogen is . Since the total charge of the ammonium ion is , we can find the oxidation state of nitrogen ( ) by the equation: Solving for : Therefore, the oxidation number of nitrogen in is .
2. Oxidation state of nitrogen in nitrate ion ( ): The nitrate ion consists of one nitrogen atom and three oxygen atoms. The oxidation state of oxygen is . Since the total charge of the nitrate ion is , we can find the oxidation state of nitrogen ( ) by the equation: Solving for : Therefore, the oxidation number of nitrogen in is .
Thus, the oxidation numbers of nitrogen in are and .