When only a little quantity of`HgCl_(2)`is added to excess `Kl(aq)` to obtain a clear solution ,which of the following is true for this solution?(no.volume change on mixing)

Options

A. Its boiling and freezing poins remain same
B. Its boiling point is lowered
C. Its vapour pressure become lower
D. Its boiling point is raised

Answer

B

Explanation

Due to the addition a complex `[HgI4]2-` willget formed as follows
`Hg^(2+)+4I^(-)rArr[HgI_(4)]^(2-)`
or `Hg^(2+)+2Cl^(-)+4I^(-)hArr [HgI_(4)]^(2-)+2Cl^(-)`
on adding we can see that `4I^(-)` ions are consumed but resultant number of particles are three.
Hence boiling point gets decreased.
freezing point get decreased.