1. If a dilute acid is added to an aqueous solution containing nitrate ions, NO₂^-, two different nitrogen compounds are released as gases.

2H⁺ (aq) + 2NO₂^- (aq) → H₂O (l) + NO (g) + NO₂ (g)

Which of the three statements below correctly describe(s) the process?

1. The H⁺ (aq) ion is oxidised by NO₂^- (aq)

2. Some nitrogen atoms are oxidised, and some nitrogen atoms are reduced

3. The oxidation number of oxygen remains unchanged throughout the reaction