Which of the following aqueous solutions has the lowest vapour pressure at 25 °C? (Sucrose is a non-electrolyte.)
0.025 mol kg-1 Ca(NO3)2
0.100 mol kg-1 CaSO4
0.075 mol kg-1 sucrose
0.050 mol kg-1 Naci
0.100 mol kg-1 KNO3

Sorry i don’t know i just need the points

The answers are 3.c kelvin4.b liquids only

The net force is 100

Answerthis solution will not form a precipitateexplanationsolubility equilbrium:         pbf₂(s)  ⇄ pb²⁺(aq) + 2 f⁻(aq)the solubility product expression is    (we exclude solids from the equilibrium expression).now suppose we have the trial ion product q, which we can define as    then, we can interpret  q as the product of the concentration of the ions that we have and ksp as the product of the ion concentrations that are needed to form a saturated solution.if q > ksp, then that implies that there will be a surplus of ions that exceed the amount that is required to form a saturated solution. a precipitate will then form (the precipitate continually  forms until the surplus ions are removed and q is decreased to ksp's value).if q = ksp, the saturated solution that forms is barely saturated and the precipitate will be minimal.if q < ksp, then the ion concentration will not be enough to form a saturated solution (so no precipitate).using our information, we calculate the trial ion product:     since q = 2.7  × 10⁻⁸ < ksp =  4  ×  10⁻⁸, a precipitate will not form.