Which of the following is displacement reaction?

Which of the following is displacement reaction?
  1. $\mathrm{N}_{2}(\mathrm{g})+\mathrm{O}_{2}(\mathrm{~g}) \longrightarrow 2 \mathrm{NO}(\mathrm{g})$
  2. $2 \mathrm{Pb}\left(\mathrm{NO}_{3}ight)_{2}(\mathrm{s}) \longrightarrow 2 \mathrm{PbO}(\mathrm{s})+2 \mathrm{NO}_{2}(\mathrm{g})+\frac{1}{2} \mathrm{O}_{2}(\mathrm{g})$
  3. $\mathrm{NaH}(\mathrm{s}) ~\mathrm{H}_{2} \mathrm{O}(\mathrm{l}) \longrightarrow \mathrm{NaOH}(\mathrm{aq})+\mathrm{H}_{2}(\mathrm{g})$
  4. $2 \mathrm{NO}_{2}(\mathrm{g})+2 \mathrm{OH}^{\ominus}(\mathrm{aq}) \longrightarrow \mathrm{NO}_{2}^{\ominus}(\mathrm{aq})+\mathrm{NO}_{3}^{\ominus}(\mathrm{aq})+\mathrm{H}_{2} \mathrm{O}(\mathrm{l})$

Solution

a. Combination redox reaction: $\mathrm{N}_{2}$ and $\mathrm{O}_{2}$ combines together to give $\mathrm{NO}$ (nitric oxide).
b. Decomposition redox (nitric oxide): $\mathrm{Pb}\left(\mathrm{NO}_{3}ight)_{2}$ (lead nitrate) breaks into three components.
c. Displacement redox reaction: Hydrogen of $\mathrm{H}_{2} \mathrm{O}$ is displaced by $\mathrm{H}^{\ominus}$ (hydride ion) into $\mathrm{H}_{2}$ gas.
d. Disproportionation redox reaction: $\mathrm{NO}_{2}(+4$ oxida-tion state) disproportionates into $\mathrm{NO}_{2}{ }^{\ominus}$ ($+3$ oxidation state) and $\mathrm{NO}_{2}^{\ominus}(+5$ oxidation state).
So, the correct option is (c)

Asked in: JEE-TOPICTESTS-CHEMISTRY

Practice more REDOX REACTIONS questions on Aicharya