Question

The white solid compound A decomposes quite rapidly on heating in the presence of a black substance X to form a solid compound B and a gas C. When an aqueous solution of compound B is reacted with silver nitrate solution, then a white precipitate of silver chloride is obtained along with potassium nitrate solution. Gas C does not burn itself but helps to burn other things.
What is compound B?

Answer 1

$\underset{A}{2KCl{O}_3}\stackrel{Mn{O}_2\left(X\right)}{\to }\underset{B}{2KCl}+\underset{C}{3O_2}$

When compound $B$ i.e. $KCl$ react with silver nitrate ($AgN{O}_3$) then white ppt. of silver chloride is formed along with potssium nitrate solution.

$KCl+AgN{O}_3\to KN{O}_3+\underset{whiteppt.}{AgCl}$

Black substance X=Manganese dioxide

Gas $C$ i.e. oxygen $O_2$ does not burn but it is an essential component for burning.