Answer:
The molecular mass of the nonionic solutes is 124,90 g/m
Step-by-step explanation:
This is the formula for boiling point elevation.
ΔT = Kb . m
Where ΔT = Tb (solution) - Tb (pure solvent)
Where Kb = the ebullioscopic constant
Where m = molality (moles of solute in 1kg of solvent)
Kb for water is 0,512°C/molal
100,680°C - 100°C = 0,512°C/molal . m
0,680°C = 0,512°C/molal . m
0,680°C /0,512 molal/°C = m
1,32 molality (This are my solute moles in 1kg (1000g) of solvent but I have just 390 g, so let's build the rule of three)
1000 g _____ 1,32 moles
390 g ______ (3,90 g . 1,32 moles) / 1000 g = 0,5148 moles
Molecular mass = g/ mol (mass/moles)
64,3 g /0,5148 moles = 124,90 g/m