This is a quick summary of the concepts we kept in mind this week:
Boyle's Law: volume of a fixed quantity of gas at constant temperature is inversely proportional to pressure.
P1V1=P2V2
Charles's Law: volume is directly proportional to temperature
V1/T1=V2/T2
Gay-Lussac's Law: Pressure and temperature is directly proportional to pressure
P1/T1=P2/T2
--->Combined gas law: P1V1/T1=P2V2/T2
Avogadro's Law: volume of gas at constant temperature and pressure is directly proportional to the tnumber of moles (n) in a gas
V1/n1=V2/n2
---> Ideal gas law: PV=nRT
Standard temperature and pressure (STP)
- 0C and 1.000atm
- 1 mole of gas = 22.4L
Molar Mass: M=m/n (M=Molar mass, m=mass, n=moles)
PV=nRT ---> PV=(m/M)RT
Density is mass over volume
PV=(m/M)RT--->m/v=PM/RT
Effusion
Grahm's Law of Effusion: r1/r2=Square root of (M2/M1)
Ideal Gasses v. Real Gasses
Ideal gasses are volume-less masses. They ignore attracting/repelling force as well. However, in real gasses, these are all taken into account.
Corrected ideal Gas equation (+ Van der Waals)
(P+n^2a/V^2)(V=nb)=nRT
a represents interaction part of molecules. b represents volume component of molecules.
General trends:
- Pressure is usually less than expected
- volume is usually greater than expected
- Ideal: small, nonpolar molecules, high temperatures, low pressure
- Non-ideal: low temperature, high pressure.
In class, we worked on ConcepTests as well as worksheets to become familiar with the concepts.
Main Ideas
I felt it was difficult to understand the different concepts because of the lack of time (at least for me, even though I only lost three days). The white boarding helps me (I think) because I learn best with examples and worked out problems. I also was disappointed because I had to rush through the task chains tonight. I hope you'll have them up again before the test! Other than that, I feel comfortable with the general trends and relationships between volume, pressure, and temperature.
