Question

In $\left[Fe\right(CN{)}_5\left(N{O}^{+}\right){]}^{2-}$, Fe has +3 state. It can be decided by:

• A. magnetic measurement
• B. colligative property
• C. colour
• D. hybridisation

Answer 1

The correct option is A magnetic measurement

As we know,
magnetic moment $=\sqrt{n(n+2)}$, n is no of unpaired electron.
$\left[Fe\right(CN{)}_5\left(N{O}^{+}\right){]}^{2-}$
So its magnetic moment will tell us about number of unpaired electrons in Fe, By which we can calculate its oxidation state.