An aqueous solution of an inorganic compound (X) shows the following reactions : (i) It decolourises an acidified KMnO_4 solution accompanied with evolution of oxygen gas. (ii) It liberates iodine from acidified potassium iodide solution. (iii) It gives brown precipitate with alkaline KMnO_4 solution with evolution of oxygen gas. (iv) It removes black stains from old oil paintings. Identify (X) and give chemical reactions for steps (i) to (iv).

An aqueous solution of an inorganic compound (X) shows the following r

1.	An aqueous solution of an inorganic compound (X) shows the following reactions : (i) It decolourises an acidified KMnO_4 solution accompanied with evolution of oxygen gas. (ii) It liberates iodine from acidified potassium iodide solution. (iii) It gives brown precipitate with alkaline KMnO_4 solution with evolution of oxygen gas. (iv) It removes black stains from old oil paintings. Identify (X) and give chemical reactions for steps (i) to (iv).
Answer» Solution :Since X REMOVES black stains from old oil paintings, it is HYDROGEN peroxide `H_2 O_2` `(i) underset((X))(5H_2 O_2) + 2K MnO_4 + 3H_2 SO_4 to K_2 SO_4 + 2MnSO_4 + 8H_2 SO_4 + 5O_2` (ii) `H_2 O_2 + 2KI + H_2 SO_4 to I_2 + K_2 SO_4 + 2H_2 O` (iii) `underset((X))(3H_2 O_2) + 2KMnO_4) to underset("Brown PPT")(2MnO_2 +2KOH + 3O_2 + 2H_2 O` (iv) `4H_2 O_2 + underset("(black)")(PBS) to underset("white")(PbSO_4) + 4H_2 O`