Chemistry Post lab Calculations

Manroop Bhandal
Chemistry 106 Lab Section 6
September 17, 2020

Data:
Calculations:
A teaspoon of salt weighs approximately 7.78 grams per teaspoon. Knowing this, calculate the grams of salt you used to make your two solutions in part one of the experiment.
█(Solution #1:1.25 teaspoons*(7.78 grams)/(1 teaspoon)=9.73 grams of salt was used for solution one.)
Solution 2:0.75 teaspoons*(7.78 grams)/(1 teaspoon)=5.84 grams of salt was used for solution two.
Determine how many kilograms of water you used to make your two solutions in the Freezing Point part. Water has a density of 0.998 g/mL, but you will have to convert cups to mL to make this calculation.
1 cup*236.588 mL*0.998g/(1 mL)*(0.001 kg)/(1 gram)=0.236 kilograms of water was used to make each solution from part one of the experiment
Use the masses of water and salt you used in the freezing points to calculate the theoretical freezing point depression.
T_(freezing for solution #1)=(1.86°C)/m*m*i
=(1.86°C)/m*(0.166 moles)/(0.236 kg)*2=-2.62°C
T_(freezing for solution #2)=(1.86°C)/m*m*i
=(1.86°C)/m*(0.100 moles)/(0.236 kg)*2=-1.57°C
Use the temperature data for the solutions actual freezing point depression and its freezing point depression.
Type equation here.

Post Lab Questions:
How did the theoretical freezing temperatures of your solutions compare to the temperatures you measured?
How did the theoretical boiling temperature of the solution you made compare to its actual boiling temperature?
Discussion:
Write a brief summary of your experiment. As part of this, you have to describe:
What you were trying to accomplish
The goal of this experiment for students to learn about colligative properties by having performed this experiment in three parts. The first part of the experiment consisted of students trying to determine the freezing point by freezing distilled water that has two solutions with different amount of salts added to them. Then students will measure the temperatures of the two solutions after they had been frozen for three hours and melted halfway after being taken out of the ice cube tray. The second part of this experiment had students accomplish the goal of making ice cream, to observe how using the salt solute can lower the freezing point of water, so that they are also able to observe the solution mixed of milk, cream, and sugar along with any additional additives to freeze. Essentially students were once again determining freezing point to be able to observe the colligative properties of aqueous solutions. The third part of the experiment was for students to accomplish observe the boiling points of the a just distilled water being boiled versus a solution of distilled water and salt being boiled.
What your experimental approach was
The experimental approach to observe the colligative properties of aqueous solutions to record their freezing and boiling points. In the first part of the experiment the freezing point was observed and recorded by having made a solution of salt and water, with solution one containing 1.25 cups of salt and 1 cup of water and with solution two containing 0.75 cups of salt and 1 cup of water. These two solutions were then placed in the freezer for three hours and then placed into two different cups and had their temperatures measure three times within one-minute increments after they had melted half way in the cups. The second part of the experiment was for students to once again record the freezing points by having recorded the temperature of the ice cream being made every five minutes and also having taken the temperature of the ice cream once it had been made. However, the colligative properties that were observed in this part of this experiment specifically was observing salt being able to lower the freezing point of water, so that students were able to accomplish the making of the ice cream. The third and final part of the experiment was for students to observe the boiling points of two solutions, one being with just distilled water and the other being with salt and distilled water. The temperatures of the two solutions had been recored only after the solutions had reached their true boiling point (after the temperature was stabilized as much as it could be).
What your results were
Please refer to the data section for the results & observations.
What sorts of things might have caused your solution’s actual freezing points to differ from their theoretical points?

What sorts of things might have caused your solution’s actual boiling point to differ from its theoretical point?
What role does salt play in making ice cream? Could you have frozen the milk/cream/other ingredients without it? Explain.