Chemistry Unit 10 Ch 13

properties of gas

-compressibility -factors affecting gas pressure-amount of gas, volume, temp

spray can

-high pressure inside -valve opens -gas punches on liquid -pushes it out

Kinetic energy types

-translational energy (gas molecules move in through space in a straight line) -rotational energy () -vibrational energy ()

real gases

1. have volume-effects V 2. heave IMF-effects P differs the most when it's small V, high P, low temp (so IMF break)

kinetic molecular theory of gases

1.Gases are made up of particles with no defined volume but with a defined mass. In other words their volume is miniscule compared to the distance between themselves and other molecules. 2.Gas particles undergo no intermolecular attractions or repulsions. This assumption implies that the particles possess no potential energy and thus their total energy is simply equal to their kinetic energies. 3.Gas particles are in continuous, random motion. 4.Collisions between gas particles are completely elastic. In other words, there is no net loss or gain of kinetic energy when particles collide. 5.The average kinetic energy is the same for all gases at a given temperature, regardless of the identity of the gas. Furthermore, this kinetic energy is proportional to the absolute temperature of the gas.

elastic collisions

An elastic collision is an encounter between two bodies in which the total kinetic energy of the two bodies after the encounter is equal to their total kinetic energy before the encounter. Elastic collisions occur only if there is no net conversion of kinetic energy into other forms.

gas laws

Gases consist of tiny (submicroscopic) molecules which are in continuous, random motion. The distance between molecules is large compared with the size of the molecules themselves. The volume occupied by a gas consists mostly of empty space. Gas molecules have no attraction for one another. Gas molecules move in straight lines in all directions, colliding frequently with one another and with the walls of the container. No energy is lost by the collision of a gas molecule with another gas molecule or with the walls of the container. All collisions are perfectly elastic. The average kinetic energy for molecules is the same for all gases at the same temperature, and its value is directly proportional to the absolute temperature.

atm conversion

One atm. equals 760.0 mm Hg One atm equals 101.325 kPa 760.0 mmHg equals 101.325 kPa

gay-lussac's law

P1/T1=P2/T2

boyles law

P1V1=P2V2

ideal gas law

PV=nRT pressure, volume=number mols, temp in k, universal gas constant

pressure cooker

SLIDE 28

Dalton;s law collecting a gas over water

SLIDE 69

Avodagro's hypothesis

Vαn Avogadro's law states that, "equal volumes of all gases, at the same temperature and pressure, have the same number of molecules". For a given mass of an ideal gas, the volume and amount (moles) of the gas are directly proportional if the temperature and pressure are constant. V/n=k

pressure and particles(n)

as one increases, so does the other

ideal v real gases

attraction between particles is real so gas can condense or solidify when compressed or cooled because IMF

result of KMT assumptions 1 & 2

compressibility-particales can be forced to come closer under pressure

gas exerts..

gas exerts pressure in all direction

t and p

increase together

compressibility

measure of how much the volume of matter decreases under pressure

combined gas law

p1v1/t1=P2V2/T2

each collisions except a force

pressure=force/area pa=n/m^2

grahams law of effusion

ratea/rateb=√mwb/mwA)

daltons law

total pressure = all the pressures added together

r

universal gas constant =8.31(LxkPa)/(Kxmol) =0.0831(Lxatm)/(Kxmol)

charles law

v1/t1=v2/t2

v and p

volume and pressure together