Question

Explain, in terms of activity, why HCl(aq) reacts with Zn(s), but HCl(aq) does not react with Cu(s).

Answer 1

Despite the fact that, both Cu and Zn are solid, there is a salient difference among them. In the periodic table, Zinc locates above the H2, so it's more active than the hydrogen, but Copper locates below the Hydrogen, so it's less active. That's why, HCl (aq) reacts with Zn (s) -- more active one, but does not react with Cu (s).

Answer 2

Explanation :

According to the reactivity series, the metals are arranged of the reactivity from the highest to the lowest.

Reactivity series is used to determine the products of the single displacement reactions. As we know that in a single displacement reaction, the most reactive metal displaces the least reactive metal.

From the given reactivity series we conclude that,

In the case of Zn and HCl, Zn metal is more reactive metal than the hydrogen. So, Zn metal can displaces the hydrogen metal from its solution and form zinc chloride and hydrogen gas as a product.

And in case of Cu and HCl, we know that the copper is less reactive metal than the hydrogen metal. So, copper can not displace hydrogen metal form its solution that means there is no product formed.

The reactivity series of metal are shown below.