We’re being asked to calculate the mass percent of ethylene glycol (C2H6O2) solution to have a boiling point of 107.1 oC.
Recall that the boiling point of a solution is higher than that of the pure solvent and the change in boiling point (ΔTb) is given by:
The change in boiling point is also related to the molality of the solution:
i = van’t Hoff factor
m = molality of the solution (in m or mol/kg)
Kb = boiling point elevation constant (in ˚C/m)
Recall that the molality of a solution is given by:
We go through the following steps to solve:
Step 1. Calculate the molality
Step 2. Calculate the mass of solute and solvent
Step 3. Calculate the mass percent
Determine the required concentration (in percent by mass) for an aqueous ethylene glycol (C2H6O2) solution to have a boiling point of 107.1 oC.
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What scientific concept do you need to know in order to solve this problem?
Our tutors have indicated that to solve this problem you will need to apply the Boiling Point Elevation concept. If you need more Boiling Point Elevation practice, you can also practice Boiling Point Elevation practice problems.