A solution of ethanol CH3CH2OH and water that is 10.% ethanol bymass is boiling at 98.7°C. The vapor is collected and cooled untilit condenses to form a new solution.
Calculate the percent by mass of ethanol in the new solution.Here's some data you may need:
| normal boiling point | density | vapor pressure at 98.7°C |
| ethanol | 78.°C | 0.79gmL | 1563.torr |
| water | 100.°C | 1.00gmL | 725.torr |
Be sure your answer has the correct number of significantdigits.
Note for advanced students: you may assume the solutionand vapor above it are ideal.
