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 the general name of substances like X?

Answer 1

The reaction is decomposition of potassium chlorate

$\underset{A}{{2KCl{O}_3}_{\left(s\right)}}\stackrel{Mn{O}_2}{\to }\underset{B}{2KC{l}_{\left(s\right)}}+\underset{C}{{3O_2}_{\left(g\right)}}$

$KCl+AgN{O}_3⟶AgCl\downarrow KN{O}_3$

Here $X$ is $Mn{O}_2$ & acts as catalyst .