(Cg) Chapeter 7: The Gas Phase

Front 1

Mathematical Relationships Between Units Used for Gasses

Back 1

1 atm = 760 mm Hg = 760 torr = 101.325 kPa

Front 2

Ideal Gas

Back 2

A gas that has no intermolecular forces and occupies no volume

Front 3

Relationship between real gases and ideal gases

Back 3

most gases will deviate from the characteristics of the ideal gases but under certain conditions they will demonstrate the properties of an ideal gas.

Front 4

The Kinetic Molecular Theory of Gasses was made in reference to what?

Back 4

The theory was stated in reference to the behavior of ideal gasses but can be applied with some modification to normal gasses

Front 5

Nature of gases

Back 5

One interesting thing about gases is that they all show the same physical properties regardless of chemical identity.

Front 6

Assumption of the Kinetic Molecular Theory

Back 6

1) Gases are made up of particles of negligible volume with respect to the container
2) Gases have no intermolecular forces
3) Gases are in continuous random motion
4) Collisions between gases are elastic
5) Average kinetic energy is proportional to the absolute temperature.

Front 7

What is the function of the Boltzman constant?

Back 7

It interrelates the macroscopic world with the microscopic world

Front 8

What is the molar volume of a gas at 0 degrees cels and at at 1 atm?

Back 8

22.4 L/mol

Front 9

Relationship between molecular speed of the molecule and the size of the molecule.

Back 9

As the temperature goes up, the speed of the molecule will also go up. However, this relationship will be offset by the size of the molecule. The larger the molecule the slower it will move and the more energy it will need to keep up the speed with which it a smaller particle will move.

Front 10

Diffusion

Back 10

The moment of gas molecules through a mixture

Front 11

If two gases are at the same temperature, what will be their average kinetic energy?

Back 11

The average kinetic energy of the two molecules will be the same. The only difference will be the speed. If the molecule of one gas are larger than the molecules of another gas then the gas with the larger mass will move slower even though the kinetic energy will be the same

Front 12

Effusion

Back 12

The rate at which gasses move through a small opening

Front 13

Relationship between rate at which one gas will effuse to its molar mass.

Back 13

The rate at which one gas will effuse through an opening is inversely proportional to the square root of their molar masses. This means that if you have a gas that has a molar mass that is four times that of another it will travel half as fast.

Front 14

Moles of gas per volume

Back 14

The moles of gas, irrespective of the identity of the gas, is a constant. For every one mole of gas you will have a volume of 22.4 liters. This is also given by the equation n/v where n is the number of mole (in this case, 1) and v is the volume of the gas (in this case 22.4).

Front 15

Important point about the gas constant R

Back 15

There are two types of units for this gas constant. each one can only be used when it is consistent with the units used for the other variable. you need to inspect the units of the other variables to make sure that they are consistent with the version of the gas constant that you are using

Front 16

If you are given the pressure of a gas and the temperature of the same gas, how would you find the density?

Back 16

Well you know that all gases have a volume of 22.4 liters per mole at one atm. All you need to do is multiply but the conversion factors to find the new mole. Keep in mind that if you increase the pressure then the pressure goes down so the new pressure needs to be on the bottom. Also, if you have a greater temperature then that needs to go on the top because you are increasing the temperature.

Front 17

Boyle's Law

Back 17

This law states that pressure and volume are inversely related. As one goes up the other goes down. This is given by the equation PV=PV

Front 18

Charles Law

Back 18

This law state that there is a direct proportion between temperature and volume. As the pressure of a container goes up the volume will go up as well. This is given by the equation V/T = V/T

Front 19

Dalton's Law of Partial Pressure

Back 19

This law state that for a given container containing a number of gasses, the total pressure on the container is the sum of the individuals pressures of the gasses themselves.

Front 20

How do you find the partial pressure of a single gas?

Back 20

You take the total pressure that you have in the container and multiply it by the mole fraction of the gas you are looking at

Front 21

What is the deviation from the ideal gas law when pressure is increased?

Back 21

When the pressure is increased the intermolecular forces are also increased (an ideal gas has no intermolecular forces). Also, at higher pressure the volume of the gas is going to be less than would be predicted by the ideal gas law. However, at very high pressure, the volume will be larger than would be predicted by the ideal gas law since the particles are larger and take up more space

Front 22

What is the deviation from the ideal gas law when temperature is increased?

Back 22

When the temperature is decreased the intermolecular attraction of the gas particles causes the gas to have a smaller volume than what would be predicted by the gas law.

Front 23

Van Der Walls Equation of State

Back 23

This equation attempts to correct for the deviations from the ideal gas law.