Do Now (3 min)When you raise the temperature, what happens

to the velocity of particles in a gas?

Turn in your Do Nows!

The Gas Laws4-15-10

Cornell Notes“Ping” Game

AgendaDo NowCornell Notes (3 gas laws)“Ping” activity - outside if we can get through

notes efficiently

Why do our ears hurt sometimes when we fly on airplanes?

Airplane ear is the stress exerted on your eardrum when the air pressure in your middle ear and air pressure in the environment are out of balance.

You may experience airplane ear at the beginning of a flight when the airplane is climbing, or at the end of a flight when the plane is descending

Fast changes in altitude cause air pressure changes that can trigger airplane ear

PressureForce per unit areaMeasured in atmospheres (atm)Gas particles exert pressure when they

collide with the walls of the containerThe more collisions, the higher the pressure

TemperatureMeasure of the average kinetic energy (energy

of motion) of all the particles in a sample of matter.

Properties of GasesProperties of gases can be modeled using

math

V = volume of the gas (L)T = temperature of the gas (K)

ALL temperatures must be in KELVINS!n = amount of moles of gasP = pressure (atmospheres, atm)

Ring of Ping ActivityAs a class we are going to MODEL the

properties of a gas:VolumeTemperaturePressure

Ring of Ping ActivityWhen we get outside, everyone will form a

circle – this will be our “container”3 students will act as gas molecules

Walk in straight linesBump into walls of container and each other

(elastic collisions)Stay at the same speedDo your best to model the particles we saw in

the simulator yesterday

Ring of Ping ActivityContainer people:

You must say “ping” every time a molecule bumps into you

1 person will record the number of “pings”1 person will be time keeper

ExpectationsAbsolutely NO TALKING in the hallway

If ONE person talks, we go back to the classroom and take notes

NO HORSEPLAY!If ONE person if off task, we go back to the

classroom and take notes and we will not be going outside anymore for the rest of the school year

We will all be returning to the classroom at the end of class, where attendance will be taken

Boyle’s LawP α 1/V

Pressure and volume are INVERSELY proportional if moles and temperature remain constant

When P goes up, V goes down and vice versa

P1V1 = P2V2

Robert Boyle (1627-1691). Son of Earl of Cork, Ireland.

Boyle’s LawBoyle’s LawA bicycle pump is a

good example of Boyle’s law.

As the volume of the air trapped in the pump is reduced, its pressure goes up, and air is forced into the tire.

Charles’s LawV α T

Volume and temperature are DIRECTLY proportional IF moles and pressure remain constant

When V goes up, T goes up

V1 = V2

T1 T2

Jacques Charles (1746-1823). Isolated boron and studied gases. Balloonist.

Charles’s BalloonHeat up the air (raise the

tempreature), the volume increases (balloon inflates)

Gay-Lussac’s LawP α T

Pressure and temperature are DIRECTLY proportional IF moles and volume remain constant

When P goes up, T goes up

P1 = P2

T1 T2

Joseph Louis Gay-Lussac (1778-1850)

Combined Gas LawGood news! We don’t have to memorize all

three laws! Since they’re all related, we can combine them into ONE equation!

• If you only need one of the other gas laws, you can cover up the item that is constant and you will get that gas law!

= P1 V1

T1

P2 V2

T2

Boyle’s Law

Charles’ Law

Gay-Lussac’s Law

Exit SlipAnswer the following questions on a separate sheet of

paper using the information from “The Ring of Ping”

What happened to the pressure when we increased the temperature?

What happened to the pressure when we decreased the volume of the container?

What happened to the volume of our “balloon” when we decreased the temperature?

You must hand in your answers in order to leave the classroom!