Question

Ferrous ion changes to X ion on reacting with acidified hydrogen peroxide. The number of d-electrons present in X and its magnetic moment (in BM) are respectively

• A. 6 and 6.93
• B. 5 and 5.92
• C. 5 and 4.9
• D. 4 and 5.92

Answer 1

Answer: (B)

Ferrous ion ( $Fe^{2 +}$ ) changes to ferric ion $F e^{3 +}$ on reacting with acidified $H_{2}O_{2}$ as.

$2Fe^{2 +}+H_{2}O_{2}+2H^{+} \rightarrow 2Fe^{3 +}+2H_{2}O$

Electronic configuration of $F e^{3 + \, }$ $= 1\text{s}^{2}2\text{s}^{2}2\text{p}^{6}3\text{s}^{2}3\text{p}^{6}3\text{d}^{5}$

Number of $\text{d}$ -electrons = 5

Magnetic moment $= \, \sqrt{n \left(\right. n + 2 \left.\right)} \, = \, \sqrt{5 \left(\right. 5 + 2 \left.\right)} \, = \, 5.92 \, BM$