Answer:
D
Explanation:
Copper has a more positive reduction potential than Hydrogen and is below Hydrogen in the reactivity series. So it can't displace H+ from diluted acids. Therefore Cu doesn't form Cu salt and a gas
Fe, Zn and Mg are above Hydrogen in the electrochemical series and can displace Hydrogen as follows
Fe(s) + 2HCl(aq) ----> FeCl2 +H2 (g)
Mg(s) + 2HCl(aq) ----> MgCl2 (aq) +H2 (g)
So iii is wrong
Zn(s) +2HCl(aq) ----> ZnCl2(aq) +H2 (g)
