Question

In nitroprusside ion, the iron and NO exist as Fe(II) and NO+ rather than Fe(III) and NO. These forms can be distinguished by:

• A. (A) estimating the concentration of iron
• B. (B) measuring the concentration of CN -
• C. (C) measuring the solid-state magnetic moment
• D. (D) thermally decomposing the compound

Answer 1

Answer: (C)

(C) measuring the solid-state magnetic moment

Answer 2

Explanation:
In nitroprusside ion, the iron and NO exist as Fe(II) and NO+ rather than Fe(III) and NO. These forms can be distinguished by measuring the solid-state magnetic moment.Nitroprusside ion is [Fe(CN)5NO]2−. If the central atom iron is present here in Fe2+ form, its effective atomic number will be 26−2+(6×2)=36 and the distribution of electrons in valence orbitals (hybridised and unhybridized) of the Fe2+ will beIt has no unpaired electron. So this anionic complex is diamagnetic. If the nitroprusside ion has Fe3+ and NO, the electronic distribution will be such that it will have one unpaired electron i.e. the complex will be paramagnetic.Thus, magnetic moment measurement establishes that in nitroprusside ion, the Fe and NO exist as F(II) and NO+ rather than Fe(III) and NO.Hence, the correct option is (C).