Question

Which of the following is a redox reaction?

• A. Reaction of $H_2SO_4$ with $NaOH$
• B. In atmosphere, formation of $O_3$ from $O_2$ by lightening
• C. Formation of oxides of nitrogen from nitrogen and oxygen by lightening
• D. Evaporation of $H_2O$

Answer 1

Answer: (C)

(a) Neutralisation reaction
(b) $3O_2 \to 2O_3$, allotropic formation
(c) $N_2 + O_2 \to 2NO$
$N_2$ is reduced and $O_2$ is oxidised.
(d) In evaporation of $H_2O$, state changes only.