[JoyceV]

I badly need help on answering these... Prof gave us some examples but nothing like these one's 

Freezing Point Depression:
List the following aqueous solutions in order of decreasing freezing point: 0.075m Glucose; 0.085m LiBr; 0.030m Zn(NO3)2

Vapor Pressure Lowering:
1. The concentrations of two solutions are as follows: (1) 5.0g of ethylene glycol, C2H6O2, in 100g of H2O; (2) 8.0g of Glucose, C6H12O6, in 100g H2O. Which solution has the higher vapor pressure?

2. Calculate the vapor pressure at 30 degrees Celsius of a 3.0 molal solution of ethylene glycol assuming that the vapor pressure of a solution containing a non-volatile solute is proportional to the mole fraction of the solvent.

Osmotic Pressure:
1. An aqueous solution of urea has a freezing of -0.52 degrees Celsius. Predict the osmotic pressure at 37 degrees Celsius. Assume that the molarity and molality are the same.

[curiouscat]

What formulae do you know?

[AWK]

http://en.wikipedia.org/wiki/Freezing_point_depression
http://en.wikipedia.org/wiki/Vapor_pressure
http://en.wikipedia.org/wiki/Osmotic_pressure

[JoyceV]

What formulae do you know?

Freezing Point = ΔT_F = m•K_F / ΔT_F = Freezing Point Solvent - Freezing Point Solution
Vapor Pressure = P_A = X_AP_A°
Osmotic Pressure ~ πV = nRT / π = MRT

[AWK]

For ionic compounds the vant Hoff isotonic factor is extremely important