Question

A metal X with dull appearance do not react with water. But it reacts slowly with dilHCl to form its respective salt Z. Find X and Z.

• A. X and Z are Cu and CuCl₂ respectively
• B. X and Z are Ag and AgCl respectively
• C. X and Z are Pb and PbCl₂ respectively
• D. X and Z are Mg and MgCl₂ respectively

Answer 1

The correct option is C

X and Z are Pb and PbCl₂ respectively

The metal X is lead. The surface of metallic lead is protected by a thin layer of lead oxide, PbO. This gives it a dull appearance. It does not react with water under normal conditions. But it reacts with dilute HCl to form lead chloride.
$Pb+2HCI\dot{a}PbC{I}_2+H_2$