Addition of HgI2 to KI (aq.) shows decrease in vapour pressure. Why?
HgI2 forms a complex with KI and therefore number of particles in the solution decreases.
HgI2 + 2KI K2[HgI4]
Vapour pressure is a colligative property, decrease in number of solute particles will increase the vapour pressure. Therefore it will show increase in vapour pressure not decrease.
HgI2 + 2KI K2[HgI4]
Vapour pressure is a colligative property, decrease in number of solute particles will increase the vapour pressure. Therefore it will show increase in vapour pressure not decrease.