Chapter 14- Gas Laws
Which constant is used when the pressure is given in atm?
.0821 L x atm
What are the standard units of pressure?
1 atm 101.3 kPa 14.7 psi 760 mmHg
What are the standard units of temperature
273 K 0 degrees C
Which constant is used when the pressure is given in kPa?
8.31 L x kPa
What factors affect gas pressure?
Amount of gas, volume, and temperature
What does Dalton's law state?
At constant volume and temperature, the total pressure exerted by a mixture of gases is equal to the sum of the partial pressures of the component gases
What does Boyle's law state?
For a given mass of gas at constant temperature, the volume of the gas varies inversely with pressure
Will a reaction occur closer to a gas with a higher or lower molar mass?
Higher because the lighter gas on the other side travels faster
Do gases of heavier or lighter MOLAR MASS travel faster?
Lighter (smaller in terms of molar mass not space!)
Under what conditions do real gases differ from ideal gases?
Low temperatures and high pressures
What are the characteristics of an ideal gas?
No volume and no IMF's
What is the formula that represents Dalton's law?
P(total) = P1 + P2 + P3 +...
What is the formula that represents Boyle's law?
P1 x V1 = P2 x V2
What is the formula that represents the combined gas law?
P1 x V1/ T1 = P2 x V2/ T2
What is the formula that represents Gay-Lussac's law?
P1/T1 = P2/T2
What is the formula that represents the ideal gas law?
PV= nRT (Where n=moles and R= constant)
What is the formula that represents Graham's law of effusion?
Rate A/ Rate B= the square root of molar mass B/ molar mass A
How do you convert from kelvin to Celsius? From Celsius to kelvin?
Subtract 273 (K to C) Add 273 (C to K)
Partial pressure
The contribution each gas in a mixture makes to the total pressure
What is the relationship between molar mass and rate of diffusion and effusion?
The gases with the lowest molar mass diffuse and effuse at a faster rate
Compressibility
The measure of how much the volume of matter decreases under pressure
What does Gay-Lussac's law state?
The pressure of a gas is directly proportional to the Kelvin temperature if the volume remains constant (container must be rigid)
Effusion
The process that involves the movement of gas molecules when escaping through holes of a container
What does Graham's law of effusion state?
The rate of effusion of a gas is inversely proportional to the square root of the gas's molar mass
What is the relationship between how ideal a gas is and it's size?
The smaller the gas, the more ideal
Total pressure
The sum of all the partial pressures in a mixture
Diffusion
The tendency of molecules to move toward areas of lower concentration until the concentration in uniform throughout
What does Charles's law state?
The volume of a fixed mass of a gas is directly proportional to it's Kelvin temperature if the pressure is kept constant (container must be flexible)
Why are gases more easily compressed?
There is a lot of space between particles in a gas
What is the combined gas law?
This describes the relationship among pressure, temperature, and volume when the amount of a gas is constant
When would you use the ideal gas law?
This is used when the amount of a substance is not constant
What is the formula that represents Charles's law?
V1/T1 = V2/T2
What are the characteristics of a real gas?
Very small volume, very weak IMF's
Which formula do you use when a variable is constant?
When a variable is constant, use the formula that does not include it
