Question

Write a balanced half-reaction for the oxidation of gaseous nitric oxide to aqueous nitrous acid in acidic aqueous solution. Be sure to add physical state symbols where appropriate.

Answer 1

Explanation:

Reaction for oxidation of gaseous nitric oxide to aqueous nitrous acid is as follows.

            $NO(g) \rightarrow HNO_{2}(aq)$

By adding water, we will balance the oxygen atoms on both the sides as follows.

          $NO(g) + H_{2}O(l) \rightarrow HNO_{2}(aq)$

Now, we will balance the hydrogen atoms by adding $H^{+}$ ions as follows.

         $NO(g) + H_{2}O(l) \rightarrow HNO_{2}(aq) + H^{+}(aq)$

Now, we will add $OH^{-}$ ions on both the sides in order to neutralize $H^{+}$ ions.

      $NO(g) + H_{2}O(l) + OH^{-}(aq) \rightarrow HNO_{2}(aq) + H^{+}(aq) + OH^{-}(aq)$ ..... (1)

We will combine the $H^{+}$ and $OH^{-}$ ions in order to form water in equation (1) and cancelling the common terms as follows.

            $NO(g) + OH^{-}(aq) \rightarrow HNO_{2}(aq)$

Now, we will balance the charge on both the sides as follows.

         $NO(g) + OH^{-}(aq) \rightarrow HNO_{2}(aq) + 1e^{-}$

Thus, we can conclude that the balanced half-reaction equation is as follows.

         $NO(g) + OH^{-}(aq) \rightarrow HNO_{2}(aq) + 1e^{-}$