In a study of aqueous solution of thorium nitrate, the freezing point depression of `0.0703^(@)C` is observed for a `9.6 mmol kg^(-1)` of the solution. How many ions are present in one thorium nitrate unit? "(`K_(f)` for` H_(2)O=1.86 K m^(-1)`)"

Explanation

Van't Hoff factor `(i)` =`"Total number of ions in solution"/"Number of ions initially"`
or `i=(DeltaT_(f))/(K_(f)xxm) =0.0703/(1.86xx9.6xx10^(-3))`
`i=4 ` or total number ions/unit