Question

Which of the below metal nitrate decomposes to give free metal after heating it?

• A. $Pb{\left(N{O}_3\right)}_2$
  
• B. $Hg{\left(N{O}_3\right)}_2$
  
• C. $Al{\left(N{O}_3\right)}_3$
  
• D. None

Answer 1

The correct option is B

$Hg{\left(N{O}_3\right)}_2$

Mercuric nitrate after heating, decomposes to give free metal.

$2Hg(N{O}_3{)}_2->2Hg+4N{O}_2+2O_2$

$Al{\left(N{O}_3\right)}_3$ and $Pb{\left(N{O}_3\right)}_2$ will give their repective nitrites and oxygen.