4/19 Chemistry Class and homework due 4/26

Hi folks,

Thanks to the fact that the weather folks told us there was some very scary weather coming (turns out it was quite a bit later than they predicted) we canceled class yesterday.  However, with the video and the material in this email, I'm really hoping you take the time to get to know the gas laws and entropy.

If you feel you need more discussion of the material, this website does a decent run down of the material I talked about in the lecture.  http://chemistry.bd.psu.edu/jircitano/gases.html

This one does a nice job with the material as well.  http://physics.info/gas-laws/

For homework this week do the following THREE assignments.

In your own words, create descriptions of four of the gas laws covered in the lecture;  Guy Lussac's, Avogadro's, Boyle's, and Charles law.   Be sure to give real world situations to explain each law.  You can use the experiments we did today in class as examples if you wish.  Explain how each situation demonstrates the law.

Also, answer the following questions on entropy.

1.  What is a definition of entropy (there are quite a few…it's a messy concept)?

2.  Describe how phase change is a change in entropy.

3.  Describe how stoichiometry can show a change in entropy.

4.  If you had a certain amount of gas in a container and increased the amount of volume, how would that effect the entropy of the gas?

Also, Go to this website  http://highered.mheducation.com/olcweb/cgi/pluginpop.cgi?it=swf::100%::100%::/sites/dl/free/0023654666/117354/Ideal_Nav.swf::Ideal%20Gas%20Law%20Simulation

First off, notice that for all the following scenarios you are looking at what happens to pressure as you change the variables of volume, temp, or moles (# of actual molecules).

1.  When you first load the web page, the default is "Graph pressure vs Volume (see upper left side).  

a.  What happens to the size of the container when you increase the volume?

b.  What happens to the pressure when you increase the volume?

c. What happens to temperature when you increase the volume?

d. What happens to the number of moles when you increase the volume?

e.  Of volume, pressure, temperature and moles, which are held constant?

f. Would you say that pressure and volume are proportional or inversely proportional?  In other words, do they both increase and decrease or does one increase while the other decreases?

g. Which of the laws is this representing?

2.  Now click on the temperature button and do the following questions.

a.  What happens to the pressure of the container when you increase the temperature?

b.  What happens to the temperature when you increase the pressure?

c. What happens to volume when you increase the temperature?

d. What happens to the number of moles when you increase the temperature?

e.  Of volume, pressure, temperature and moles, which are held constant?

f. Would you say that pressure and temperature are proportional or inversely proportional?  In other words, do they both increase and decrease or does one increase while the other decreases?

g. Which of the laws is this representing?

3.  Now click on the N button and do the following questions.

a. When you change N, what is changing?

b.  What happens to the pressure of the container when you increase the n?

c.  What happens to the n when you increase the pressure?

d. What happens to temperature when you increase the n?

e. What happens to the volume when you increase the n?

f.  Of volume, pressure, temperature and moles, which are held constant?

g. Would you say that pressure and n are proportional or inversely proportional?  In other words, do they both increase and decrease or does one increase while the other decreases?

h. Which of the laws is this representing?