Thursday, December 9, 2010

Gas gas gas




Half of our classmates were gone today...
because of ....... don't know...
Denna wasn't here today so I am the scriber for today

We started the class with a demontration.  Mr. Liberman put some melted dry ice into a styrofoam box and put a manometer,this manometer has a empty metal ball, into that box.  And the pressure went down because the moles which is in that ball starts to move slow.  Through this experiment we could make sure that when temperature goes down then pressure goes down and temperature goes up then pressure goes up.

After Mr. Liberman finish off with this experiment, we wanted him to dump the melted dry ice on the floor.
And he did....Twice :)
The melted dry ice started to move around the floor like when we spill some water on the hot pan.
We were all excited about the movement of  these little particles.
Also Mr. Liberman dumped the ice over my head accidently!
Korri screamed and called 911 immediately
So that's why I am in hospital right now...
hehe I'm just kidding~
Actually he poured vapor over my head. It just feel coooool~

Today, we learned about the Ideal Gas Equation.
The three important gas laws, Boyle's, Charles', and Avogadro's, derived relationships between two physical properties of a gas, while keeping other properties constant.
When we rearrange to a more familiar form we get                    PV = nRT
*In this equation R is the gas constant.

The conditions 0 *C and 1 atm are called Standard Temperature and Pressure (STD).
At STR R = (1 atm x 22.414L) / (1 mol x 273 K)
R = .0821
And experiments show that at STP, 1 mole of an ideal gas occupies 22.414 L.
If you know the formula with STD, we could convert to different forms.
The important thing is the value of R won't change!

Here is an example
 What is the volume(in liters) occupied by 49.8g of HCl at STP?
T = 0*C = 273K
P = 1 atm
n = 49.8g x (1 mol / 36.45g HCl) = 1.37 moles
V = (1.37 mol x 0.0821 x 273 K) / (1atm)
V = 30.6L

I hope you guys understand what I explained...
If you want more information about the ideal gas equation, I recommended to visit :


Today's homework is a Worksheet and Pre-Lab


The next scribe will be Denna M.

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