Two isomers X and Y with the formula `Cr(H_2O)_5ClBr_2` were taken for experiment on depression in freezing point. It was found that one mole of X gave depression corresponding to 2 moles of particles and one mole of Y gave depression corresponding to 3 moles of particles. The structural formulae of X and Y respectively are

Options

A. `[Cr(H_2O)_5Cl]Br_2 , [Cr(H_2O)_4Br_2 ] ClH_2O`
B. `[Cr(H_2O)_5Cl]Br_2 , [Cr(H_2O)_3ClBr_2 ]2H_2O`
C. `[Cr(H_2O)_5Br]BrCl , [Cr(H_2O)_4ClBr]Br H_2O`
D. `[Cr(H_2O)_4Br_2]Cl. H_2O , [Cr(H_2O)_5Cl]Br_2`

Answer

D

Explanation

X gave depression corresponding to 2 moles of particles.
`X=[Cr(H_2O)_4Br_2]Cl.H_2O hArr [Cr(H_2O)_4Br_2]^(+) Cl^(-)`
Y gave depression corresponding to 3 moles of particles.
`Y=[Cr(H_2O)_5Cl]Br_2 rArr [Cr(H_2O)_5Cl]^(2+) + 2Br^(-)`