what is the oxidation number of the nitrogen atom (N) in NH3 and in HNO3

Answer 1

To determine the oxidation number of nitrogen in both compounds, we can follow these guidelines:

1. In ammonia (NH₃):

   • The oxidation number of hydrogen (H) is +1.
   • Let the oxidation number of nitrogen (N) be \( x \).
   • The overall charge of the molecule is neutral (0).
   • The equation can be set up as follows: \[ x + 3(+1) = 0 \] Simplifying this gives: \[ x + 3 = 0 \ x = -3 \]
   • Therefore, the oxidation number of nitrogen in NH₃ is -3.

2. In nitric acid (HNO₃):

   • The oxidation number of hydrogen (H) is +1, and the oxidation number of oxygen (O) is usually -2.
   • Let the oxidation number of nitrogen (N) be \( x \).
   • The overall charge of the molecule is neutral (0).
   • The equation can be set up as follows: \[ +1 + x + 3(-2) = 0 \] Simplifying this gives: \[ +1 + x - 6 = 0 \ x - 5 = 0 \ x = +5 \]
   • Therefore, the oxidation number of nitrogen in HNO₃ is +5.

In summary:

• The oxidation number of nitrogen in NH₃ is -3.
• The oxidation number of nitrogen in HNO₃ is +5.