Select the correct answer from A, B, C, D and E —

(A) Nitroso Iron [II] sulphate

(B) Iron [III] chloride

(C) Chromium sulphate

(D) Lead [II] chloride

(E) Sodium chloride.

The compound responsible for the brown ring in the brown ring test for identifying the nitrate ion.

A blue crystalline solid 'X' on heating gave a reddish brown gas 'Y', a gas which relits a glowing splint and a residue which is black. Identify X and Y, and write the equation for the action of heat on X.

State your observation when —

Copper is heated with concentrated nitric acid in a hard glass test tube.

Choose the correct answer from the choices given – The brown ring test is used for detection of:

(A) CO₃^2-
(B) NO₃^1–
(C) SO₃^2-
(D) C1^1-