Question

Sodium nitroprusside gives a violet colour with sulphide ions. The compound (formed in this test) is:

• A. Na2[Fe(NO)(CNS)5]
• B. H3[Fe(CN)6]
• C. Na4[Fe(NOS)(CN)6]
• D. Na4[Fe(NOS)(CN)5]

Hint:

Sulphide converts nitrosyl (NO) to NOS in nitroprusside's 5-cyanide complex.

Answer 1

The Correct Option is D

Option A wrongly uses thiocyanate (CNS) instead of cyanide. Option B has no nitrosyl group. Option C has 6 CN instead of correct 5. Option D correctly keeps 5 CN + 1 NOS with 4 Na+ balancing 4- charge.

\[\boxed{Na_4[Fe(NOS)(CN)_5]}\]