Grahams Law of Effusion
Effusion rate of a gas is inversely proportional to the square root of its molar mass.
The rate of effusion of a gas is inversely proportional to the time for the gas to effuse
through a barrier.
LecSup15)Comparetheeffusionratesofh
Lec Sup #15 aka lab!
Find the molar mass of a gas where the volume of the flask used to collect the gas is
250. ml, the mass of the condensed liquid is 1.30 g, the pressure of the atmosphere is
1.01 atm, and the temperature of the room is 25.0 degrees cel
Pa is pressure of gas a (na is moles)
Pt is total pressure (nt is total moles)
Each gas in a mixture behaves independently from the others*.
Total pressure at a constant T and V is determined by the total number of moles
present.
LS16)A sample of KClO3 is
Effusion and Diffusion
Average KE of any collection of gas molecules = mu2, at a given Temperature.
Lighter particles and heavier particles will have the same average KE.
Lighter particles have higher rms.
Distribution of molecular speed for N2 At 0C and
Deviations from ideal behavior
High Pressure causes deviation from ideal behavior.
Temperature also affects ideal behavior.
As temperature increases, properties of gases approach ideal behavior.
Ideal gas molecules are assumed to occupy no space and have
Input numeric answer
LS #12: If 2.5 grams of zinc are allowed to react with excess hydrochloric acid, how
many Liters of hydrogen gas will be generated? The room temperature is 24.0 degrees
Celsius and the atmospheric pressure is 99.8 kPa?
Input Answer
Da
Unit 3
Day 1: 10.1-10.2
Housekeeping
Bellwork: What is pressure?
Big Idea: How do they know how much chemicals to put in an airbag so it properly
inflates?
Day 1: 10.1-10.2
Housekeeping
Exam.studying on weekend, look over old tests
Bellwork: Write down al
Memorize: Standard Pressure:
typical pressure at sea-level
1 atm
101.3 kPa
760 torr
760 mmHg exactly
1.013 bar
1 bar exactly is 1 X 105 Pa or 1 X 102 kPa
14.7 psi
Mercury Barometers
Glass tube more than 760 mm long and closed at one end.
Invert into liqui
LS #6: Solving for V
What volume does a gas occupy if 1.00 mol of gas is at 101.3 kPa and 0.0C?
23.4 L
B) 0.0 L
C) .22 L
22.4 L
STP
Standard temperature and pressure.
T= 0C (273.15K) & 1 atm.
Molar volume of an ideal gas at STP:
LS7)Atennisballhasavolumeo
Consider the Following:
Temp (T)
Volume (V)
The Temperature-Volume relationship.
The volume of a fixed amount of gas at a constant pressure is directly proportional
to its absolute temperature.
Commonly expressed as:
LS #3: Solving for V
If a 25.0 L ballo
Ideal Gas
Housekeeping: Studying for the Exam
Bellwork: Think about how P, T, V, and amount of gas relates (2 at a time)give
examples.
4 Variables needed to describe state of a gas:
Temperature (T)
Pressure (P)
Volume (V)
Number of moles (n)
Consider the