Suppose two liquids (A and B) are mixed together and a phase diagram constructed for this real solution (shown in green in the graph below). Vapour pressure lines are also drawn in grey for the ideal version of this solution. What is the partial vapour pressure of A over the real solution having x_B = 0.4? If 2 mol of A are mixed with 8 mol of B, what is the total vapour pressure over the real solution at equilibrium? Which substance is more volatile, A or B? Explain how you determined this. Which interaction is stronger for this real solution, the solute Interaction with itself, or the solute interaction with the solvent? Briefly explain your reasoning.
Measure or calculate and record the following (in grams):
mass of the empty Erlenmeyer flask 1:
mass of the Erlenmeyer flask 1 plus the mixture sample:
mass of the mixture sample:
mass of the Erlenmeyer flask 1 and the remaining contents after drying of sand:
mass of Erlenmeyer flask 1 and dry sand
(2nd weighing)
Subtract (a) from (e) to obtain the mass of sand in the sample:
Measure or calculate and record the following (in grams):
mass of an empty Erlenmeyer flask 2:
mass of Erlenmeyer flask 2 and dry NaCl
(1st weighing)
mass of Erlenmeyer flask 2 and dry NaCl
(2nd weighing)
mass of Erlenmeyer flask 2 and dry NaCl
(3rd weighing) if necessary
measured mass of dry NaCl:
Assignment Questions (all work must be shown for all calculations):
Using the results of your lab, complete all the questions below.
Upload one picture that is representative of your experiment with this report to the appropriate D2L Brightspace Assignments folder.
Complete Data Table 1 located in the Procedure. Make sure to include all your work for all the calculations performed.
The amount of sodium chloride in the original mixture may also be determined indirectly by subtracting the SiO2 mass from the initial sample mass. Calculate the expected mass of NaCl using this method.
Calculate the percent difference of NaCl (Note: This is not % Error, but it is a similar calculation. This is an error calculation that checks precision between the results of the two methods from the following equation: (Note: the unit for this calculation is â% differenceâ)
% difference=measured mass-mass by subtractionmass by subtraction x 100
What is the mass percent of each component in your mixture: SiO2, and NaCl? (Note: the units for this calculation are â% SiO2â and â% NaClâ)
mass percent=mass of componenttotal mass of sample x 100
Error Analysis: Was your % difference from Assignment Question 4 within 10%? Why or why not? Did your two mass percentages in Assignment Question 5 add up to 100%? Why or why not? What were your biggest sources of error in this experiment? What would you do differently if you were to repeat this experiment? Explain.
What type of properties (physical or chemical) are we using to separate the mixture in this laboratory. Explain your answer.
A mixture is found to contain 0.69 g SiO2, 1.05 g of cellulose, and 2.17 g of calcium carbonate. What is the mass percentage of SiO2 in this mixture?
Assume you have a mixture of NH4Cl, sand, and salt and access to a regular chemistry laboratory. How would you separate the three?Write out what your procedure would be in numbered steps. Please research the answer to this question and properly cite your source. It is alright to research using the internet. However, Wikipedia, Yahoo Answers, Ask.com, and other non-scientific sources cannot be used.