Question

Mark the correct statements:

• A. $\text{Hg}$ forms an amalgam with iron
• B. $\text{Hg}$ vapour is non-poisonous
• C. $\text{Hg}$ is monovalent in mercurous compound
• D. Oxysalts of $\text{Hg}$ are thermally unstable

Answer 1

The correct option is D Oxysalts of $\text{Hg}$ are thermally unstable

(A)Mercury forms amalgams with all metals except iron and platinum. Hence, statement A is incorrect.

(B) Mercury vapour is poisonous. Hence option B is incorrect.

(C) Hg forms univalent mercurous compounds but these compounds exist as dimers such as $Cl-Hg-Hg-Cl$. Hence, statement C is incorrect.

(D) Oxysalts of mercury are thermally unstable. They decompose on heating to form metallic mercury and oxygen. Hence, statement D is correct.

Hence, the correct option is $\text{D}$