Salt Analysis

A white amorphous powder (A) on heating yields a
colourless, non-combustible gas (B) and a solid (C).
The latter compound assumes a yellow colour on heating
and changes to white on cooling. (C) dissolves in dilute
acid and the resulting solution gives a white precipitate
on adding K₄Fe(CN)₆
solution.

(A) dissolves in dilute HCl with the evolution of gas,
which is identical in all respects with (B). The gas (B)
turns lime water milky, but the milkiness disappears with
the continuous passage of gas. The solution of (A), as
obtained above, gives a white precipitate (D) on the
addition of excess of NH₄OH and passing H₂S. Another
portion of the solution gives initially a white precipitate
(E) on the addition of sodium hydroxide solution, which
dissolves on further addition of the base. Identify the
compounds (A), (B), (C), (D) and (E).