Question

$Zn$ gives $H_2$ gas with $H_{2}S{O}_4$ and $HCl$ but not with concentrated $HN{O}_3$ because

• A. $N{O}_3^{-}$ is reduced in preference to Hydronium ion.
• B. In electrochemical series, $Zn$ is above hydrogen
• C. $HN{O}_3$ is weaker acid than $H_{2}S{O}_4$ and $HCl$
• D. $Zn$ acts as an oxidizing agent when reacts with $HN{O}_3$.

Answer 1

The correct option is A

$N{O}_3^{-}$ is reduced in preference to Hydronium ion.

$HN{O}_3$, being a strong oxidizing agent, forms $N{O}_2$ and $NO$ instead of releasing $H_2$ gas. Further $H^{+}$ ions are oxidized to water.