Lab 15: Evaporation and Intermolecular Attractions




I.Introduction: The purpose of this lab was to observe 5 substances and observe the differences in temperature of these substances as they evaporated based on their intermolecular forces. We had to measure the temperature of these 5 substances using a LabQuest device  over a 240 second period and record the Initial and Final temperatures of these substances. Finally we had to find the difference (Final- Initial) and compare these to the other substances based on their intermolecular forces.

 II. Pre Lab Table: 


 III. Data Table: 
IV. Lab Questions: 
1.) Explain the differences in the difference in temperature of these substances as they evaporated. Explain your results in terms of intermolecular forces.
The differences in temperature of the five substances varied a lot  because the intermolecular forces of every substances were different. H2O had the smallest difference because its intermolecular force was strong, so it was harder for it to evaporate. Methanol had the largest difference because its intermolecular force was the weakest, so it evaporated easier. The temperature of Glycerin increased because it absorbed energy from the surrounding air rather than evaporating because it had three hydrogen bonds, so its intermolecular force is very strong.Glycerin had the strongest intermolecular force out of all of the substances.
2.) Explain the difference in evaporation of any two compounds that have similar molar masses. Explain your results in terms of molar masses and intermolecular forces.
Ethanol,Methanol, and n-Butanol all have one hydrogen bond, so they have the same intermolecular forces. However their molar masses differed. Methanol has the largest difference because its molar mass was the smallest, so its bonds are not as strong and it evaporates faster. Ethanol has the second largest difference because its molar mass was the second smallest. Lastly, n-Butanol had the smallest difference because its molar mass was the largest, so its bonds are the strongest and it evaporates slowest.

 3.) Explain how the number of -OH groups in the substances tested affects the ability of the tested compounds to evaporate. Explain your results in terms of intermolecular forces.
The number of OH groups in substances affects the ability of the test compounds to evaporate because it affects how strong or weak their intermolecular bonds are. For example, Methanol has one -OH group and has the lowest molar mass, so its difference in temperature is the greatest because its intermolecular force (hydrogen bond) is the weakest since it evaporates so easily. Ethanol has one -OH group and the second lowest molar mass, so its difference in temperature is the second greatest and as a result it also evaporates pretty fasts. This shows based on their OH bonds they have different molar masses and intermolecular forces which causes different substances to evaporate differently. 



















Comments

Post a Comment

Popular posts from this blog

Lab 18: Alka Seltzer and the Ideal Gas Law

Image
I. Introduction:   In this lab the purpose was to measure the reaction between Alka Seltzer and water and to  determine the mass of the gas produced. What we did was, first we smashed up an alka seltzer tablet and put it inside a balloon. We then put the balloon over a graduated cylinder full of water and as the two substances combined, CO2 was produced and collected in the balloon. After all the gas had been created we measured the circumference of the balloon. We then emptied the gas and refilled the balloon with water until it had the same circumference. From this we were able to measure the water and find the volume. Through a series of calculations , we were able to conclude that the mass of CO2 was around 1.26 grams in our experiment. II. Data:  III. Calculations:  (Setup) IV: Analysis Questions:  1. Discuss an area in this lab where experimental error may have occurred. There are many instances where an experimental error may have occurred  For exam
Read more

Lab 11: Flame Test Lab

Image
I. Introduction:  The purpose of this lab was to observe how certain atoms react and release energy within different compounds and solutions. We performed the lab by taking samples of the nine compounds and held them over a bunsen burner. Then, we observed any color or texture changes and recorded them. We also had identify two unknown chlorine compounds using flame tests. To identify the two unknowns, we compared their flame colors to those of the other eight compounds and assumed the solution based of this. II. Pre Lab Questions: III. Data:  IV. Analysis Questions:  Picture of LiCl emitting Pink Light:
Read more

Lab 12: Electron Configuration Battleship

Image
I. Picture of My Setup:  II. Biggest Challenge: My biggest challenge playing was trying to do the electron configurations in my head. Also trying to solve the f block configuration in my head was extremely challenging. III. What I Learned: I learned how to solve electron configuration faster and efficiently using the periodic table. 
Read more