When $Cl_2$ water is added to a salt solution containing chloroform,the chloroform layer turns violet. The salt contains:

Which of the following is correctly matched?

Chromyl chloride test is used for the detection of:

In the test for $SO_4^{2-}$,the white precipitate of sulfate is soluble in which of the following solutions?

How do you account for the following observations?
$(a)$ Though alkaline potassium permanganate and acidic potassium permanganate both are used as oxidants,yet in the manufacture of benzoic acid from toluene,we use alcoholic potassium permanganate as an oxidant. Why? Write a balanced redox equation for the reaction.
$(b)$ When concentrated sulphuric acid is added to an inorganic mixture containing chloride,we get a colourless pungent-smelling gas $HCl$,but if the mixture contains bromide,then we get red vapours of bromine. Why?

An anion solution gives a white precipitate with $AgNO_3$ solution. The precipitate dissolves in dilute ammonia due to the formation of: