Chemistry lab reports
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Report2.docxCHM1046 Lab - REPORT # 2
Last name, First name: Student ID:
1) Date of the experiment:
2) Experiment #:
3) Experiment Title:
4) Purpose of the Experiment –
5) Background/Brief Introduction–
6) Experimental Procedure: (Passive Mode)
7) Experimental Results/Data:
Freezing point of Solvent: 16.6°C
Freezing point of solution: 14.4°C
Depression of freezing point (AT) 2.2°C
Mass acetic acid: 26.25 g
Mass of solute (unknown) 2.00 g
Actual Molar Mass= 122.12 g/mol
% error
8) Results and Discussion:
9) Conclusions:
10) Question(s):
1. If your experimental error is greater than 10%, use the correct molar mass, and calculate what the T should have been.
2. If a few drops of water got into the acetic acid solution what would be the effect on the freezing point? (Remember that the water acts age a solute.) Next, explain logically the effect on the molar mass.
3. What is the freezing point of a 50% by weight solutions of ethylene glycol, C2H602, in water ("antifreeze")? Mal. Wt. of ethylene glycol is 62.0 g/mol. To start, write out what 50% ethylene glycol means to get the masses to use.
4. When the molar mass of acetic acid CH3COOH is determined in the solvents benzene C6H6 or carbon tetrachloride CC14 its molecular weight is 120 g/mol. To explain why,
a. State the main intermolecular forces that are between acetic acid molecules.
b. What intermolecular forces must the solvents use to dissolve the acetic acid?
c. Are these solvents capable of breaking all of the intermolecular interactions of acetic acid? If not, which ones?
d. Calculate the molar mass of acetic acid from its chemical formula given above. The experimental molecular weight is 120 g/mol. in the above solvents, what can you conclude about what form acetic acid molecules take when they dissolve in these solvents?
