JEE Advanced 2025 · Paper 2 · Chemistry Q1

ChemistrySingle correct+3 / -1Question 33 of 48

During sodium nitroprusside test of sulphide ion in an aqueous solution, one of the ligands coordinated to the metal ion is converted to

\ce{NOS-}

\ce{SCN-}

\ce{SNO-}

\ce{NCS-}

Answer and worked solution

Official answer: A

Sulphide attacks the nitrosyl ligand of sodium nitroprusside, giving a violet complex:
$\ce{[Fe(CN)5NO]^2- + S^2- -> [Fe(CN)5NOS]^4-}$

The NO ligand is converted to $\ce{NOS-}$ .

JEE Advanced 2025 · Paper 2, Chemistry question 1