0.005 mol of non-electrolyte was dissolved in 50g of benzene. Calculate depression of a freezing point of this solution
To calculate the depression of freezing point, we can use the equation:
ΔT = Kf * m
Where:
ΔT = depression of freezing point
Kf = cryoscopic constant (freezing point depression constant) for the solvent
m = molality of the solution
First, let's find the molality of the solution:
Molality (m) is defined as moles of solute per kilogram of solvent.
Given:
Amount of solute = 0.005 mol
Mass of solvent (benzene) = 50g
Now, we need to convert the mass of the solvent to kilograms:
Mass of solvent = 50g = 0.05 kg
Next, we can calculate the molality:
m = (0.005 mol) / (0.05 kg)
m = 0.1 mol/kg
Now, we need to find the cryoscopic constant (Kf) for benzene. The Kf value for benzene is 5.12 °C·kg/mol.
Finally, we can plug in the values into the equation ΔT = Kf * m:
ΔT = (5.12 °C·kg/mol) * (0.1 mol/kg)
ΔT = 0.512 °C
Therefore, the depression of the freezing point of the solution is 0.512 °C.