Identify the substances based on the information given below and choose the correct option:
The reddish brown liquid S is dissolved in water. When ethyne gas is passed through it, turns colourless.
Chlorine water
Bromine water
Iodine solution
Potassium permanganate solution
Ferric nitrate solution
The deliquescent salt P, turns yellow on dissolving in water, and gives a reddish brown precipitate with sodium hydroxide solution.
The pale green solid R turns reddish brown on heating. Its aqueous solution gives a white precipitate with barium chloride solution. The precipitate is insoluble in mineral acids.
The white crystalline solid Q is soluble in water. It liberates a pungent smelling gas when heated with sodium hydroxide solution.