Chemistry - Salt Analysis Question with Solution | TestHub

A colourless water soluble solid $A$ on heating gives equimolar quantities of $B$ and $C.B$ gives dense white fumes with $\mathrm{HCl}$ and $C$ does so with ${\mathrm{NH}}_3.B$ gives brown precipitate with Nessler's reagent and $C$ gives white precipitate with nitrates of ${\mathrm{Ag}}^{+},{\mathrm{Pb}}^{+}$and ${\mathrm{Hg}}^{+}.A$ is