An aqueous solution is 1.00 molal in KI. Which change will cause the vapour pressure of the solution to increase?

A 0.0020 m aqueous solution of an ionic compound [Co(NH₃)₅(NO₂)]Cl freezes at $$-$$ 0.00732^oC. Number of moles of ions which 1 mol of ionic compound produces on being dissolved in water will be (K_f = $$-$$1.86^oC/m)

0.5 molal aqueous solution of a weak acid (HX) is 20% ionised. If K_f for water is 1.86 K kg mol^$$-$$1, the lowering in freezing point of the solution is

1.00 g of a non-electrolyte solute (molar mass 250 g mol^$$-$$1) was dissolved in 51.2 g of benzene. If the freezing point depression constant, K_f of benzene is 5.12 K kg mol^$$-$$1, the freezing point of benzene will be lowered by