Question

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

• A. Iron and $H_{2}S{O}_4\left(aq\right)$
• B. Iron and steam
• C. Copper and $HCl\left(g\right)$
• D. Sodium and $HCl\left(aq\right)$

Answer 1

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

As per the reactivity series, Copper falls below Hydrogen which means its reactivity is lower than that of hydrogen, so it cannot displace hydrogen from hydrochloric acid.