Q47 / 180 · AIIMS 2018 (26 May) · Chemistry

Which of the following can be reduced easily?

  • Correct answer
    A
    $\mathrm{V}(\mathrm{CO})_6$
  • B
    $\mathrm{Mo}(\mathrm{CO})_6$
  • C
    $\left[\mathrm{Co}(\mathrm{CO})_4\right]^{-}$
  • D
    $\mathrm{Fe}(\mathrm{CO})_5$

Solution

$\mathrm{V}(\mathrm{CO})_6$ can be easily reduced to $\left[\mathrm{V}(\mathrm{CO})_6\right]^{-}$. $\mathrm{V}(\mathrm{CO})_6$ has a total of 17 bonding electrons, hence it is very reactive and unstable. $\left[\mathrm{V}(\mathrm{CO})_6\right]$ on the other hand has complete set of 18 bonding electrons as an electron is added into the bonding orbital when $\mathrm{V}(\mathrm{CO})_6$ gets reduced to $\left[\mathrm{V}(\mathrm{CO})_6\right]^{-}$. All others have 18 bonding electrons.

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

More Coordination Compounds Questions