Find your unknown assignments here:
Download the following unknown data file then copy and paste your unknown data sets to a new excel with tabs titled Raoults Law and Henry’s Law
For Raoult’s law:
Create and calculate columns for
-
- Solute mol fraction
- Solute moles
- Solute molality
Determine the identity of your unknown by using the grams of solute and the mols of solute.
Graph:
1. Vapor Pressure (VP) vs mol fraction water
2. VP vs mol fraction solute (label correctly with identity of your solute)
3. VP vs moles solute
4. VP vs molality solute
For Henry’s law:
Graph the vapor pressure vs. molality of your unknown gas.
Use the slope to compare to values of Henry’s constants for the possible unknown options to determine your unknown gas.
Colligative Properties Data Analysis
Answer the following questions with respect to your completed excel data from this week. Answer to the
best of your ability, sometimes you are being asked what you think. Cite any resources that you use.
1. What were your unknowns for Raoult’s Law this week?
2. What does Raoult’s law predict, as much in your own words/understanding as possible?
3. A student creates a solution of potassium sulfide, K2S. The student calculates the moles of K2S
added from the mass of solute then continues to determine the mole fractions of both solvent and
solute. At least, the student calculates the expected vapor pressure based on the mole fraction of
solvent. Will the actual vapor pressure be higher or lower than what the student calculates?
4. Would it be possible for a solution of water with sucrose to have a vapor pressure of 0.04005 atm
at room temperature? Why or why not?
5. What were your unknowns for Henry’s Law this week?
6. List at least two different ways the pressure above a solution could be controlled or altered.
7. Other than a can of soda, think of (or look up after making an honest effort!) an example of
Henry’s Law in our day to day lives and explain how Henry’s Law applies.
must be on excel, not any other program or application for spreadsheet/graphing