New User Special Price Expires in

Let's log you in.

Sign in with Facebook


Don't have a StudySoup account? Create one here!


Create a StudySoup account

Be part of our community, it's free to join!

Sign up with Facebook


Create your account
By creating an account you agree to StudySoup's terms and conditions and privacy policy

Already have a StudySoup account? Login here

Chemistry Report 3 Freezing Point Depression

by: Pooja Dave

Chemistry Report 3 Freezing Point Depression CHM 113

Marketplace > University of Miami > Chemistry > CHM 113 > Chemistry Report 3 Freezing Point Depression
Pooja Dave
GPA 3.825

Preview These Notes for FREE

Get a free preview of these Notes, just enter your email below.

Unlock Preview
Unlock Preview

Preview these materials now for free

Why put in your email? Get access to more of this material and other relevant free materials for your school

View Preview

About this Document

This is the third chemistry report for chemistry lab 113.
General Chemistry 1 lab
Dr. Tegan Eve
Class Notes
General Chemistry
25 ?




Popular in General Chemistry 1 lab

Popular in Chemistry

This 3 page Class Notes was uploaded by Pooja Dave on Thursday September 29, 2016. The Class Notes belongs to CHM 113 at University of Miami taught by Dr. Tegan Eve in Fall 2015. Since its upload, it has received 5 views. For similar materials see General Chemistry 1 lab in Chemistry at University of Miami.


Reviews for Chemistry Report 3 Freezing Point Depression


Report this Material


What is Karma?


Karma is the currency of StudySoup.

You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!

Date Created: 09/29/16
Pooja Dave CHM 113, Section FY Freezing Point Depression with Lauric Acid Introduction: The freezing point depression is used in determining the temperature at which the system freezes. The molecules within a substance get closer together as it solidifies, the exception being water as its molecules are farther away when solid. The addition of another substance creates an impurity and can alter these molecular interactions. Freezing point lowers as solutes are added. This freezing point is found within the flat portion of the graph Time vs. Temperature in Celcius. The flat portion represents the heat of fusion during the cooling process. The temperature does not change and the molecules are being packed tightly into a solid. The freezing point of Lauric acid changes with the addition of benzoic acid, as the molecules cannot be packed as tightly into the solid state. However, it can be estimated by finding the average freezing point constant using molality and the change in temperature. Molality is used because it does not change with volume which is temperature dependent, unlike molarity. The freezing point constant for both solution is averaged together to get an approximate value for pure Lauric acid. The differences in freezing point constant for the two solutions also show how different amounts of solute can lead to different freezing points. Procedure: 1. Set up LoggerPro, labeling the x and y axis Time in second and Temperature in Celcius and connecting the temperature probe to the data collector 2. Fill a 400mL beaker with water and heat up using a hot plate until approximately 60 to 80⁰C 3. Obtain a test tube containing a solution of 0.75 g of Benzoic Acid with 8.00 g of Lauric Acid 4. Place the test tube in water bath and melt the mixture 5. Once fully melted take it out of hot water bath and add the temperature probe, hitting collect 6. Place test tube in the room temperature water bath and stir as data has started collecting 7. Determine freezing point from the graph, looking for the point when the graph straightens out 8. Repeat steps 3 through 8 but with a test tube containing the solution with 8.00 g Lauric Acid with 1.50 g Benzoic Acid Equations: ΔT = K f molessolute m = masssolvent(kg) Observations: During our experiment, the greatest error was in the data collection. The beginning of the graph was not smooth, making freezing point harder to find. There was also a gap in time from when the test tube left the water bath to the time data started collecting. Data: Molecular Weight of Benzoic Acid = 122.12 g/mol Melting point of pure Lauric Acid = 43.2⁰C Moles of 0.75 g BA = 0.00614 mol Molality of 0.75g BA/8.00g LA = 0.768 mol/kg Change in Temperature = 3.2 ⁰C Kfof 0.75g BA/8.00g LA = 4.17 Moles of 1.5g BA = 0.0122 mol Molality of 1.5g BA/8.00g LA = 1.54 mol/kg Change in Temperature = 6.1 ⁰C Kfof 1.5g BA/8.00g LA = 3.84 Calculations: 0.75g BA/8.00g LA: 1mol × Moles of BA = 0.75g 122.12g = 0.00614 mol 0.00614mol Molality (m) = 0.008kg = 0.768 mol/kg ΔT = 40 – 43.2 = 3.2 ⁰C 3.2 ⁰C = (0.768) K f K = 4.17 f 1.50g BA/8.00g LA: × 1mol Moles of BA = 1.50g 122.12g = 0.0122 mol 0.0122mol Molality (m) = = 1.54 m 0.008kg ΔT = 37.1 – 43.2 = 6.1 ⁰C 6.1 ⁰C = (1.54) K f K f 3.84 Average K = f.003 Discussion and Conclusion: The average K value obtained from this experiment shows the value when f Lauric acid freezes. It represents the average freezing point constant for Lauric acid. This freezing point constant is the moment when the molecules of Lauric acid form close bonds, making it a solid. With the known melting point of Lauric acid and the molecular weight of Benzoic acid, the moles and change in temperature can be calculated. These two pieces of data can be applied to the equation to solve for freezing point constant. The differences between the solution with 0.75g Benzoic acid and the one with 1.50g Benzoic acid show how the K value chafges with more solute. The solution with 1.50g of BA had a lower K value fhan the one with 0.75g of BA. Because the K valfe is lower, the freezing point is lower meaning that it takes more energy for the solution to freeze. Our data then supports the idea that the one with the most solute interferes the most with the molecular arrangement during solid formation. Errors:  The temperature probe was first placed in the heat bath to test its temperature. This may have interfered with the collecting of data when testing the temperature as Lauric acid freezes. The initial temperature then would have been higher than in reality, and the warm temperature probe may have delayed the freezing of Lauric acid.  The time gap between taking the test tube out of the heat bath and collecting data may have cause data to be missed. This would then have altered the freezing point, making the initial temperature lower than it actually was.  Some of the Lauric acid may not have completely melted when we took the test tube out of the water bath. This would cause the freezing point to be higher than what it actually was.  Stirring the warm test tube in room temperature water bath may have disrupted the cooling of Lauric acid, as there were inconsistencies in the stirring. This would have delayed the freezing, making the freezing point lower than it actually is. Graph:


Buy Material

Are you sure you want to buy this material for

25 Karma

Buy Material

BOOM! Enjoy Your Free Notes!

We've added these Notes to your profile, click here to view them now.


You're already Subscribed!

Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'

Why people love StudySoup

Bentley McCaw University of Florida

"I was shooting for a perfect 4.0 GPA this semester. Having StudySoup as a study aid was critical to helping me achieve my goal...and I nailed it!"

Amaris Trozzo George Washington University

"I made $350 in just two days after posting my first study guide."

Jim McGreen Ohio University

"Knowing I can count on the Elite Notetaker in my class allows me to focus on what the professor is saying instead of just scribbling notes the whole time and falling behind."

Parker Thompson 500 Startups

"It's a great way for students to improve their educational experience and it seemed like a product that everybody wants, so all the people participating are winning."

Become an Elite Notetaker and start selling your notes online!

Refund Policy


All subscriptions to StudySoup are paid in full at the time of subscribing. To change your credit card information or to cancel your subscription, go to "Edit Settings". All credit card information will be available there. If you should decide to cancel your subscription, it will continue to be valid until the next payment period, as all payments for the current period were made in advance. For special circumstances, please email


StudySoup has more than 1 million course-specific study resources to help students study smarter. If you’re having trouble finding what you’re looking for, our customer support team can help you find what you need! Feel free to contact them here:

Recurring Subscriptions: If you have canceled your recurring subscription on the day of renewal and have not downloaded any documents, you may request a refund by submitting an email to

Satisfaction Guarantee: If you’re not satisfied with your subscription, you can contact us for further help. Contact must be made within 3 business days of your subscription purchase and your refund request will be subject for review.

Please Note: Refunds can never be provided more than 30 days after the initial purchase date regardless of your activity on the site.