Question

Among the following ions which one has the highest paramagnetism.

• A. $\left\lbrack Cr(H_{2}O)_{6} \right\rbrack^{3 +}$
• B. $\left\lbrack Fe(H_{2}O)_{6} \right\rbrack^{2 +}$
• C. $\left\lbrack Cu\left( H_{2}O \right)_{6} \right\rbrack^{2 +}$
• D. $\left\lbrack Zn\left( H_{2}O \right)_{6} \right\rbrack^{2 +}$

Answer 1

Answer: (B)

$\left\lbrack Fe(H_{2}O)_{6} \right\rbrack^{2 +}$

Answer 2

$\lbrack Fe(H_{2}O)_{6}\rbrack^{2 +}$ has four unpaired electrons, $\lbrack Cr(H_{2}O)_{6}\rbrack^{3 +},\mathbf{\lbrack Cu(}\mathbf{H}_{\mathbf{2}}\mathbf{O}\mathbf{)}_{\mathbf{6}}\mathbf{\rbrack}^{\mathbf{2 +}}$ and $\lbrack Zn(H_{2}O)_{6}\rbrack^{2 +}$have 3, 1, 0 unpaired electrons respectively.