Question

Which one of the following matter does not displace H2 gas from dilute HC1 or H2SO4?
(a) Mg
(b) A1
(c) Zn
(d) Cu

Answer 1

Answer:

(d) Cu

Explanation:

As H is more electropositive than copper. Cu does not displace H2

Answer 2

Copper does not displace H2 from dilute HCl and H2SO4

Explanation:

Copper is a very unreactive metal, and it does not react with hydrochloric acid. Hydrogen is more electropositive as it has more reducing power of metals than copper. Hydrogen is above copper in a metal reactivity series. Copper cannot replace the hydrogen in HCl to form CuCl2. Hence there will be no reaction.  

Cu(s) + HCl(aq) → no reaction

Mg, Al and Zn, all three reacts with HCl and H2SO4 and displace Hydrogen.