Question

Which one of the following pairs of substances on the reaction will not evolve $H_2$ gas?

• A. Iron and $H_{2}S{O}_4\left(aq\right)$
• B. Copper and $HCl\left(g\right)$
• C. Na and $C_2{H}_{5}OH$
• D. Iron and steam

Answer 1

The correct option is B Copper and $HCl\left(g\right)$

Copper will not react with $HCl$, because $Cu$ is placed below the hydrogen in electrochemical series, which means $Cu$ will not displace hydrogen from $HCl$.

$Cu+HCl⟶$ no reaction.