Intro to Gases 3 Lawshut-lhansen.weebly.com/uploads/2/9/0/6/2906938/ap... · Fixed Amount Not the...
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AP Phys 2 Unit 2.A.3 Notes Gas Laws Part 1.notebook
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2.A.3 Gas Laws Part 1:Fixed Amount Not the Stone Temple Pilots
(90's era grunge band).
Stands for: Standard Temperature and PressureDefined: 0 degrees Celsius (273 K), and 1.0 atm (1.0 E 5 Pa) of pressure.The utility of STP is that a lot of gas problems start at STP before changes occur (temp, pressure, volume, amount of gas).
Who's Heard of STP?
Gases respond predictably to changes in pressure, temperature, volume and number of particles.
For a fixed amount of gas, a change in one variable (pressure, temperature, volume) affects the others.
Intro to Gases 3 LawsDifferent gases have different expansion properties.At low densities, however, all gases exhibit identical expansion behavior.At higher densities, gas molecules interact with each other.Noninteractive gases are called Ideal Gases (a theoretical condition): they are massless, don't have electrostatic interactions or volume, and they do not collide.
Gas Laws
P1V1 = P2V2P = absolute pressureV = volume
The volume of a gas is inversely proportional to its pressure at constant temperature.From condition 1 to condition 2:
A note on units: they can be anything, as long as they're the same!Construction Set Syringe Demo.
Boyle's Law Constant TemperatureThe volume of a gas at 99.0 kPa is 30.0 m3. If the pressure is increased to 188 kPa, what will be the new volume?
Organize data first:
Example 1: Boyle's Law
AP Phys 2 Unit 2.A.3 Notes Gas Laws Part 1.notebook
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September 23, 2016
V = volumeT = temperature (Kelvins)
Charles' Law: Constant PressureThe volume of gas is directly proportional to its Kelvin temperature (constant pressure). From condition 1 to condition 2:
GayLussac's Law: Constant VolumeThe pressure of a gas is directly proportional to the Kelvin temperature (constant volume).
P = absolute pressure
T = temperature (Kelvins)
CombinedLaw:
Combined Gas LawWhen more than one variable is changed for a fixed amount of gas, use the Combined Gas Law:
Remember: these laws are for a fixed amount of gas.
T
VP
Boyle's Law:
Charles'sLaw:
GayLussac'sLaw:
CombinedLaw:
Combined Gas Law: Pictorial Aid
Example 2: A rigid steel container holds 1.00 L of methane gas at 660 kPa (abs.) when the temperature is 22 oC. What's the pressure at 45 oC?
Which Law is useful? GayLussac's.
Convert Celsius to Kelvin: 22.0 oC = 295 K 45 oC = 318 K.
HomeworkLabeled 2.A.2 in your Booklets (2016
ONLY!!)Problems 1, 2, 6 ONLY in your Booklet.
Due: Next Class.