Kinetic TheoryAll matter is in constant motion:-atoms, ions, molecules-s,l,g,p (States of Matter)

Gases:1)Gas is made of particles

-atoms/molecules-mostly empty space-weak forces between particles

2)Gas particles in constant motion-random

3)Collisions are perfectly elastic-energy transfer 100%

-T, KE-all particles have same KE

KE = 1/2mv2

constant

http://phet.colorado.edu/en/simulations/category/chemistry

Gas Properties

Gas Diffusion5.

1 T

he G

aseo

us S

tate

Ammonia (17.0g/mol)

Ammonia diffused farther in same time, lighter moves faster

Hydrogen chloride (36.5g/mol)

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Bottom:End of expt

-0K = -273°C = absolute zeroeverything freezesno KE

-Gas pressure-force created by collisions of particles on object-Atmospheric pressure-force created by collisions of particles on

an object caused by gravity-Barometer-measures pressure

1atm = 760mmHg = 101.3kPa sea level-STP = 0°C, 1atm

Phase Change-physical state of substance changes-melting, freezing, evaporating, condensing, sublimating(All examples of Physical Changes)

Gas Laws4 scientists:DaltonRobert BoyleJacques CharlesJoseph Gay-Lussac

Real Gases-particles: volume random motion collisions elastic weak attractive forces under pressure, liquefied and solidified

Ideal Gases-particles: no volume random motion collisions elastic no attractive forces under pressure, not liquefied and solidified

Since real gases are mostly empty space and attractive forces are extremely weak, real gases act like ideal gases in most situations!!!

http://phet.colorado.edu/en/simulations/category/chemistry

Dalton’s Law of Partial Pressures:-In a mixture of gases, the total pressure is the sum of the pressures for each gas in the mixture.

PT = P1 + P2 + P3 + …. V=constantT=constant

ex/A scuba tank is filled with He, O2, and N2. The He is used since it cuts down on the risk of the diver contracting the “Bends”. How much He is in the tank if the tank is filled with 20atm N2, 4atm O2, and the total pressure is 24.6atm?

http://www.youtube.com/watch?v=N5xft2fIqQU

Boyle’s Law-Volume of a gas varies inversely with pressure.

P1V1 = P2V2 T=constantV, P

ex/A balloon partially filled to capacity with N2. The balloon has 400mL of N2 at 1.6atm pressure. What will happen to the pressure if the volume is decreased to 350mL by someone squeezing on the balloon?

Charles’ Law-Volume of a gas varies directly with temperature.

V1 = V2

T1 T2

ex/A balloon partially filled to capacity with N2. The balloon has 400mL of N2 at 25°C. What will happen to the volume if the temperature is increased to 45°C by someone heating it?

P=constantV, T

55 Gallon Drum

Gay-Lussac’s Law-Pressure of a gas varies directly with temperature.

P1 = P2

T1 T2

ex/A spray can of paint contains a constant volume of paint at 16atm, 25°C. What will happen if the can is heated to 120°C? It will explode at 30atm.

V=constantP, TT must be in K

Combined Gas Law:-Ties Boyle’s, Charles’, Gay-Lussac’s Laws into one. Memorize this one!!! Others are derived from it!

P1V1 = P2V2

T1 T2

ex/You go to Party City to buy your friend a mylar balloon since she is graduating. The conditions inside the store are 22°C. The balloon is filled with 5.6L of He at a pressure of 2atm. You put the balloon in your car and drive home. The temp inside your car is 34°C, a hot Summer day. Since the balloon is mylar, it only expands to 5.7L. What is the final pressure of the balloon? What will probably happen to the balloon?

T=constant .:Boyle’s P=constant .:Charles’V=constant .:Gay-L’s

Ideal Gas Law:-Used to calculate number of moles for a gas.

PV = nRT n=# molesR=0.0821 L•atm

K•mol

ex/A propane tank contains 20,000L of C3H8 at 14.5atm. If the temperature outside is 35°C, how many grams of propane are in the tank?

ex/A tank of r22 (CHClF2) refrigerant has a volume of 20L at 12.8atm and contains 1200g of refrigerant, what is the temperature of the refrigerant in the tank?

Liquids:-particles in motion, slide, less random-particles held together by weak attractive forces unlike gases-KE liquid < gas-Vaporization-liquidgas, below boiling pt

-Evaporation-vaporization in open space-T, KE all particles .:Those closest to surface have enough energy to escape liquid. This is how energy is removed from the liquid and why temperature of the liquid remains the same as the liquid is heated further.-Dynamic Equilibrium-rate evaporation=rate condensation .:Process doesn’t stop. All particles have an equal chance to evaporate and condense. Adding more heat increases the rate of evaporation and decreases condensation!

-Boiling Point-Temp which vapor pressure=atmospheric pressure.:vapor escapes from liquid-Normal Boiling Point-boiling point at 1atm

ex/bpt water: Dover=100°C Nittany Mountains=94°C

Solids:-particles packed close together in organized pattern-xtal structure-particles do not move, only vibrate/rotate-KE solid < liquid

-T, KE, vibrations/rotations .:melting-Melting Point-temp solidliquid .:particles slide-no temperature increase until all solidliquid .:equilibrium between solid and liquid T, rate melting, rate solidification-Ionic Compounds- melting points since strong attraction

between particles-Covalent Compounds- melting points since weaker attraction

between particles-Amorphous-solid lacking xtal structure

.:properties solid+liquid ex/LCD, rubber, polymers, glass

-Heat of fusion-energy, 1g, melting pt solidliquid-Heat of solidification-energy, 1g, melting pt liquidsolid-Heat of vaporization-energy, 1g, boiling pt liquidgas-Heat of condensation-energy, 1g, boiling pt gasliquid