Question

A black colured compound (A) on reaction with dil. H₂SO₄ gives a gas (B) which on passing in a solution of an acid (C) gives a white turbidity (D). Gas (B) when passed in an acidified solution of a compound (E) gives a precipitate (F) soluble in dilute HNO₃ . After boiling this solution when an excess of NH₄OH is added, a blue coloured compound (G) is formed. To this solution on addition of acetic acid and aqueous K₄[Fe(CN)₆] a cholcolate precipitate (H) is obtained. On addition of an aqueous solution of BaCl₂ to an aqueous solution of (E) a white precipitate insoluble in dilute HCl is obtained. Identify the compounds from (A) to (H).

Answer 1

A - FeS, CuS, PbS, HgS, COS, NiS 

B - H₂S 

C - HNO₃ 

D - S 

E - CuSO₄ 

F - CuS 

G - [Cu(NH₃)₄](NO₃)₂ 

H - Cu₂Fe(CN)₆