Question

The compound which gives off oxygen on moderate heating is

• A. Cupric oxide
• B. Mercuric oxide
• C. Zinc oxide
• D. Aluminium oxide

Answer 1

Answer: (B)

$2\text{HgO}\stackrel{\Delta }{\to }2\text{Hg}+{\text{O}}_2\uparrow$
The meruric oxide is unstable and easily decomposes on heating.