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 do you think that black substance X and What is its function?

Answer 1

$2KCl{O}_3+Mn{O}_2⟶2KCl+3O_2$

Compound A=Potassium chlorate and Compound B=Potassium chloride

Gas C=Oxygen

Black substance X=Manganese dioxide

The general name of substance X=catalyst

$Mn{O}_2$ acts as a catalyst in decomposition.