Avagadro's Law

Avagadro's Law says that for a gas at constant temperature and pressure, the volume is directly proportional to the number of moles of gas. Equal volumes of gases at the same temp and pressure have the same amount of particles. This relationship is even true for gases at low pressures. The relationship for this law is:

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Example: We have 12.2 L containing .50 moles of oxygen at a pressure of 1 atm and a temp of 25C. If all of the oxygen is converted to ozone at the same temp and pressure, what would be the volume?

3O2-->2O3

V1=12.2L    N1=.50mol    V2=?    N2=.33 mol

.5mol x 2mol/3mol = .33mol

12.2(.33)=V2(.5) = 8.13L

Calculating Heat

To calculate heat, you use the formula Q=mcAt (A is representing delta)

Q is heat in Joules
m is mass in grams
c is specific heat in J/g degrees C
At is change in temperature

Example 1: Calculate the amount of energy in joules required to heat 454 grams of water from 5.4C to 98.6C:

Q=?   m=454g    At=93.2  Ti=5.4   Tf=98.6   c=4.184
454(4.184)(98.6-5.4)= 1.77x10^5 J OR 177 kJ

Example 2: A 2.6g sample of metal requires 15.6J of energy to change its temperature from 21C to 24C. What's the identity of the metal?

m=2.6g   Q=15.6J   Ti=21   Tf=34   c=?
15.6=2.6(c)(34-21)
C=.46 J/gC OR Iron

Temperature and Heat

The Kinetic Molecular theory states that as a substance is heated, molecules gain energy. However, we cannot measure the amount of energy in the form of heat a substance contains, but we can measure the flow of heat energy. This is always from a warm to cold body until the temperature equalizes. This change is used to measure heat flow.

Exothermic: If there's an output of energy out of the system, then the system is losing energy.

Endothermic: If there's an input of energy into the system, then the system is gaining energy.

Endothermic vs. Exothermic

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Music Video Reflection

Exciting news! After submitting Hamming and I's biodiesel music video to the American Lung Association's contest, we were notified that we made it to the top 10, along with 2 other groups from our school! Now, while waiting for the official results to come out, we have the chance to earn $250 by getting the most views on our video. To help us with this, all you have to do is press on the special link below and listen to our little ukulele tune. Thanks!!

"Most Views" Link

Biodiesel Boat Lab

Over the past few days, Hamming and I have been working on engineering, constructing, re-constructing, and finally running our biodiesel boat. We ran into many problems along the way, including multiple leaks, spilled fuel, and semi-toxic fumes coming from our homemade candle. In the end, we got somewhere around fourth place! The only thing that kept us from actually placing was that, the whole way down the track, it went side to side and bumped off the edges. We ended up making the boat out of a cut up soda can, held together by aluminum tape and lots and lots of hot glue. We also accidentally went through 3 engines before the end of it, oops. Overall, this project was super fun and also very educational because it made us creatively problem solve, while also learning about biodiesel. Here are the instructions on how to make your own: Biodiesel Boat

Music Video Project

My lab partner, Hamming Lin, and I made a music video all about biodiesel and its beneficial effects. I think it turned out pretty well. Here is a link to it! Enjoy!

"Singing to Save the World"

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