The two isomers X and Y with the formula `Cr(H_(2)O)_(5)ClBr` 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 to 3 moles of particles. The structural formulae of X and Y raspectively are

Options

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

Answer

D

Explanation

One mole of X gave depression corresponding to 2 moles of particles i.e., on ionisation X gives 2 moles of ions thus it contains only 1 ion outsaide 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 , thus it contains two ions outside the coordination sphere and its structural formula is ` [Cr (H_(2) O)_(5) ]Br_(2) `