Question
A crystalline solid X reacts with dilute HCl to liberate a gas Y. Y decolourises acidified $KMnO_4$. When a gas Z is slowly passed into an aqueous solution of Y, colloidal sulphur is obtained. X and Z could be, respectively?
A crystalline solid X reacts with dilute HCl to liberate a gas Y. Y decolourises acidified $KMnO_4$. When a gas Z is slowly passed into an aqueous solution of Y, colloidal sulphur is obtained. X and Z could be, respectively?