Chemistry: Chapter 3Chemistry: Chapter 3

States of MatterStates of Matter

Phases of Matter

4 phasesSolid, Liquid,Gas, Plasma,

Solid •Molecules packed closely together

•Definite volume

•Definite shape

•Low kinetic energy because the molecules don’t have room to move.

Liquids •Molecules move more freely, but close together

•Definite volume

•No definite shape (Takes shape of container)

•Medium kinetic energy

Liquids •Viscosity Resistance of a liquid to flow.

Ex. Honey, Oil

Gas •Molecules are far apart and can move freely

•No fixed volume

•No definite shape (Takes shape of container)

•High kinetic energy (more movement = more kinetic energy)

Plasma

Can be thought of as a gas consisting of electrons instead of atoms.

Particles have extremely large amounts of energy.

Most common phase of matter in the universe.

http://www.neok12.com/video/States-of-Matter/zX645353667e6d7a03795d51.htmShort video on plasma

http://www.brainpop.com/games/mattersorter/

Kinetic theory

• Kinetic theory

1. All matter is composed of small particles. (atoms, molecules, etc.)

2. Particles are in constant, random motion.3. These particles are colliding with each other and the walls of their container.

Kinetic Theory of Gases

1.Particles are in random, constant motion.

2. The motion of the particles is unaffected unless they collide with one another.

3.Forces of attraction among particles in a gas can be ignored under ordinary conditions.

Video on states of matterVideo on states of matter

http://www.neok12.com/video/States-of-Matter/zX0a00427e02510841527f06.htm

Pressure The force distributed over an area.

SI unit: Pascal

•Collisions between gas particles causes the pressure in a closed container.

Factors that affect Pressure

Temperature – Raising the temperature will increase the pressure.

Volume – Reducing the volume of a gas increases the pressure.

Number of Particles – Increasing the number of particles increases pressure.

http://phet.colorado.edu/en/simulation/states-of-matter

The volume of a gas varies directly (same way) with the temperature of the gas.

Temperature Volume

Temperature Volume

Ex: basketball in the summer as opposed to one in the winter

Charles’s Law

http://www.grc.nasa.gov/WWW/K-12/airplane/aglussac.html

The volume of a gas varies inversely (opposite way) with the pressure of the gas.

Pressure Volume

Pressure Volume

Boyle’s Law

http://www.grc.nasa.gov/WWW/K-12/airplane/aboyle.html

http://www.grc.nasa.gov/WWW/K-12/airplane/aboyle.html

http://www.grc.nasa.gov/WWW/K-12/airplane/aglussac.html

Charles’s Law

V1 = V2

T1 T2

P1V1 = P2V2

P1V1 = P2V2

T1 T2

Boyle’s Law

Combined Gas Law

Practice ProblemsPractice ProblemsGas LawsGas Laws

1. At a 1. At a temperaturetemperature of of 280K280K, the gas in a , the gas in a cylinder has a cylinder has a volumevolume of of 20.0L20.0L. If the . If the volume of the gas is decreased to volume of the gas is decreased to 10.0L10.0L, , what must the what must the temperaturetemperature be for the gas be for the gas pressure to remain constant?pressure to remain constant?

What do we know? Which formula do we What do we know? Which formula do we use? What are we solving for?use? What are we solving for?

2. If the 2. If the volumevolume of a cylinder is of a cylinder is reducedreduced from from 8.0L8.0L to to 4.0L4.0L, the , the pressurepressure of the gas of the gas in the cylinder will change from in the cylinder will change from 70kpa70kpa to? to?

What do we know? What formula do we What do we know? What formula do we use? What are we solving for?use? What are we solving for?

3. If a gas has a volume of 1L at a 3. If a gas has a volume of 1L at a pressure of 270kpa, what volume will it pressure of 270kpa, what volume will it have when the pressure is increased to have when the pressure is increased to 540Kpa? Assume the temperature and 540Kpa? Assume the temperature and number of particles are constant.number of particles are constant.

What do we know? What formula do we What do we know? What formula do we use? What are we solving for?use? What are we solving for?

Gas law helpGas law helpGREAT websiteGREAT website

http://www.chemteam.info/GasLaw/KMT-Gas-Laws.html

Open the science of divingOpen the science of diving

Interactive powerpointInteractive powerpoint

Phase Changes

Changing from one phase to another by decreasing or increasing kinetic energy.

Kinetic Energy

*Reversible Physical Change

Temperature and Phase Change

The temperature is one way to recognize a phase change.

The temperature will not change during the change, it will change once the transformation is complete!

gasAccording the this chart, which phase of matter has the most heat energy?

Energy and Phase Change

•Energy is absorbed or released.

•Endothermic – absorbed

•Exothermic - released

Solid – Liquid – Gas – Plasma

Energy Increases

Energy Decreases

Melting Solid Liquid

Heat of fusion – amount of energy absorbed for water

Freezing Liquid Solid

Liquid GasEnergy must be absorbed – heat of vaporization

Evaporation on the surface of a liquid at temperatures below the substances boiling point (100°C for water)

Gas Liquid

Ex. clouds

Condensation

Vaporization

Solid Gas (without changing to a liquid)

Ex. Dry ice

Sublimation

Gas Solid (reverse of sublimation)

Ex. Frost on windows

Deposition