Purpose
The purpose of this experiment is to determine the freezing points of water, 10% antifreeze, and 20% antifreeze utilizing an ice bath and a really cool thermometer.
Apparatus
Procedures
Preparing the Ice Bath 1. Fill the tub ¾ full with ice. 2. Cover the ice with a respectable amount of salt. 3. Add water and stir that bad boy, the water should be standard temperature in a fwe minutes.
Fill the test tube with any amount of water and submerge promptly
*Check the test tube every few seconds until frozen. Record temperature. Repeat with both antifreeze solutions
Data | Freezing Point (°C) | Distilled Water | 0.0°C | 10% Antifreeze | -3.5°C | 20% Antifreeze | -8.0°C |
Calculations
Questions: 1. Using the equation ΔT = Kf m, calculate the molality of the 10% antifreeze solution.
2. Use the formula molality = moles solute/kg solvent to find the number of moles in 10% antifreeze solution.
3. Using the formula molar mass = grams/moles calculate the molecular mass of antifreeze in the 10% solution.
4. Using the equation ΔT = Kf m¸calculate the molality of the 20% antifreeze solution.
5. Use the formula molality = moles solute/kg solvent to find the number of moles in 20% antifreeze solution.
6. Using the formula molar mass = grams/moles calculate the molecular mass of antifreeze in the 20% solution.
7. Average the molar masses you calculated in questions 3 and 6.
8. The formula for antifreeze is C2H6O2. Calculate its molarmass using the periodic table.
9. Calculate your percent error.
Conclusion:
This lab was a phenomenal success! The purpose of determining the freezing points of water, 10% antifreeze, and 20% antifreeze was not only accomplished, but also done so in a splendid manner. The net figures of our experiment were less than 5°C off from the established values. Of course, it goes without saying that this