Question

Which one of the following is the chemical formula of sodium nitroprusside?

• A. \( \text{Na}_2[\text{Fe(CN)}_5\text{NO}] \)
• B. \( \text{Na}_3[\text{Fe(CN)}_6\text{NO}] \)
• C. \( \text{Na}_3[\text{Fe(CN)}_5\text{NO}] \)
• D. \( \text{Na}_4[\text{Fe(CN)}_5\text{NO}] \)

Hint:

Remember the key components: sodium (Na), iron (Fe), cyanide (CN), and nitrosyl (NO). The overall charge of the complex must be balanced. Nitrosyl (NO) is often considered neutral in this context, and cyanide has a -1 charge, so \( [\text{Fe(CN)}_5\text{NO}] \) would have a -5 charge if iron were +2, but the complex ion has a -2 charge, indicating iron is in the +2 oxidation state.

Answer 1

The Correct Option is A

Sodium nitroprusside has the chemical formula \( \text{Na}_2[\text{Fe(CN)}_5\text{NO}] \). It is a complex inorganic compound consisting of two sodium cations (\( \text{Na}^+ \)) and a pentacyanonitrosylferrate(II) anion \( [\text{Fe(CN)}_5\text{NO}]^{2-} \). The iron ion is coordinated to five cyanide ligands (CN) and one nitrosyl ligand (NO).