$A$ substance on treatment with dilute $H_2SO_4$ liberates a colourless gas which produces:
$(i)$ turbidity with baryta water and
$(ii)$ turns acidified dichromate solution green.
The reaction indicates the presence of:

The brown ring test is used to detect the presence of which of the following ions?

To a solution of a colourless efflorescent sodium salt,when dilute acid is added,a colourless gas is evolved along with the formation of a white precipitate. Acidified dichromate solution turns green when the colourless gas is passed through it. The sodium salt is

The incorrect statement in respect of the chromyl chloride test is:

$A$ salt solution is treated with chloroform drops. Then it is shaken with chlorine water. The chloroform layer becomes violet. The solution contains:

Which of the following compounds will give a precipitate with $Pb(NO_3)_2$ but will not give a precipitate with $Ba(NO_3)_2$?