Question
Derive a formula for the molar mass of the solute in terms of the freezing point depression, deltaT, the freezing-point constant, Kf, and the masses of solvent, msolvent, and solute, msolute, used in an experiment like this one. SHow your work and include all unites in your final formula.
This is my attemps at the formula:
ΔT = Kf * (msolvent + msolute / nsolvent + nsolute)
This is my attemps at the formula:
ΔT = Kf * (msolvent + msolute / nsolvent + nsolute)
Answers
I think what you need to do is as follows:
delta T = Kf*molality
molality = mols solute/kg solvent
mols solute = mass solute/molar mass.
Substitute equation 2 into equation 1 for molality.
Then, substitute mols solute into the resulting equation and solve for molar mass.
delta T = Kf*molality
molality = mols solute/kg solvent
mols solute = mass solute/molar mass.
Substitute equation 2 into equation 1 for molality.
Then, substitute mols solute into the resulting equation and solve for molar mass.
I see, thanks a lot Bob!
Related Questions
What is the molar mass of a molecular solute when 5g of the solute dissolved in 150g of phenol lower...
If the freezing point of the solution had been incorrectly read 0.3degrees C lower than the true fre...
68.0g of solute were dissolved in 393 mL of benzene. The solution froze at -0.50°C. The normal freez...
A solution containing 3.22g of solute in 40.0g of 1,4-dichlorobenzene and its freezing point is 49.2...