Question:
Zinc liberates hydrogen gas when reacted with dilute hydrochloric acid whereas copper does not. Explain why ?
Solution:
Zinc (Zn) is placed above hydrogen in the activity series. It therefore, displaces hydrogen from dilute HCl.
Zn (s) + 2HCl (aq) ————-> ZnCl2 (aq) + H2(g)
Copper is placed below hydrogen and therefore, does not react with dilute HCl.
Cu (s) + HCl (aq) ———–> No action.