For 1 molal aqueous solution of the following compounds, which one will show the highest freezing point ?

Options

A. `[Co(H_(2)O)_(5)Cl]Cl_(2).H_(2)O`
B. `[Co(H_(2)O)_(4)Cl_(2)]Cl.2H_(2)O`
C. `[Co(H_(2)O)_(3)Cl_(3)].3H_(2)O`
D. `[Co(H_(2)O)_(6)]Cl_(3)`

Answer

C

Explanation

We know, `Delta T = ik_(f) xx m`
At some molality, the depression in freezing point will depend on van't Hoff factor
Lesser is the van't Hoff factor greater will be the freezing point og solution
`[Co(H_(2)O)_(5)Cl]Cl_(2).H_(2)O" "i=3`
`[Co(H_(2)O)_(4)Cl_(2)]Cl.2H_(2)O" "i=2`
`[Co(H_(2)O)_(3)Cl_(3)].3H_(2)O" "i=1` (This complex will show highest freezing point)
`[Co(H_(2)O)_(6)]Cl_(3)" "i=4`]