The 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 due to 3 moles of particles. The structural formulae of X and Y respectively are

Options

A. `[Cr(H_(2)O)_(5)Cl]Br_(2),[Cr(H_(2)O)_(4)Br_(2)]Cl*H_(2)O`
B. `[Cr(H_(2)O)_(5)Cl]Br_(2),[Cr(H_(2)O)_(3)ClBr_(2)*2H_(2)O]`
C. `[Cr(H_(2)O)_(5)Br]BrCl(H_(2)O)_(4)ClBr]Br*H_(2)O`
D. `[Cr(H_(2)O)_(4)Br_(2)]Cl*H_(2)O,[Cr(H_(2)O)_(5)Cl]Br_(2)`

Explanation

One mole of X gave depression corresponding to 2 moles of particules , i.e ., on ionisation X gives 2 mole of ions , thus it contains only one ion outside the coordination sphere and its structural formula is `[Cr(H_(2)O)_(4)Br_(2)]Cl*H_(2)O`
While Y gives 3 moles of ions , so it contains two ions outside the coordination sphere and its structural formula is `[Cr(H_(2)O)_(5)Cl]Br_(2)`
`[Cr(H_(2)O)_(4)Br_(2)]Cl*H_(2)O overset("ionisation")to`
`underset(2"ions")ubrace([Cr(H_(2)O)_(4)Br_(2)]^(+)+Cl^(-))+H_(2)O`
`[Cr(H_(2)O)_(5)Cl]Br_(2)overset("ionisation")tounderset(" 3ions")ubrace([Cr(H_(2)O)-(5)Cl]^(2+)+2B^(r^(-)))`