Increasing amount of solid `Hgl_(2)` is added to `1 L` of an aqueous solution containing `0.1 mol KI`. Which fo the following graphs do represent the variation of freezing point of the resulting with the amount of `Hgi_(2)` added?

Options

A.
B.
C.
D.

Explanation

When `H_(g)I_(2)` is added to KI:
`HgI_(2)+2KitoK_(2)HgI_(4)`
Mole` 0.05" "0.2" "0.1" "0.05`
`implies`0.05moles of are required for its complete reaction with KI.
Thus, as `HgI_(2)` is being added, number of solute molecules will decrease causing `DeltaT_(f)` to decrease [Causing `T_(g)` to increase]. When whole of KI has been converted to `K_(2)HgI_(4)` , further addition of `HgI_(2)` doesn’t change the `T_(g)` since it is a sparingly soluble salt.