Q17 / 160 · WBJEE 2015 · Chemistry

Cold ferrous sulphate solution on absorptive of NO develops brown colour due to the formation of

  • Correct answer
    A
    paramagnetic $\left[\mathrm{Fe}\left(\mathrm{H}_{2} \mathrm{O}\right)_{5}(\mathrm{NO})\right] \mathrm{SO}_{4}$
  • B
    diamagnetic $\left[\mathrm{Fe}\left(\mathrm{H}_{2} \mathrm{O}\right)_{5}\left(\mathrm{N}_{3}\right)\right] \mathrm{SO}_{4}$
  • C
    paramagnetic $\left[\mathrm{Fe}\left(\mathrm{H}_{2} \mathrm{O}\right)_{5}\left(\mathrm{NO}_{3}\right)\right]\left[\mathrm{SO}_{4} \mathrm{l}_{2}\right.$
  • D
    diamagnetic $\left[\mathrm{Fe}\left(\mathrm{H}_{2} \mathrm{O}\right)_{4}\left(\mathrm{SO}_{4}\right)\right] \mathrm{NO}_{3}$

Solution

Cold FeSO, solution on absorption of NO develops brown colour due to the formation of $[Fe(H_{2}O)_{5}(NO)]SO_4$ $\mathrm{FeSO}_{4}+\mathrm{NO}+5 \mathrm{H}_{2} \mathrm{O} \rightarrow [Fe(H_{2}O)_{5}(NO)]SO_4$ This complex has 3.89 BM magnetic moment shows that it has 3 unpaired electrons

Hence, the correct answer is option: 'A'.

Relevant Questions