Things to PonderThings to Ponder• Scratch a dog and you’ll find a

permanent job.

• Money will buy a fine dog, but only kindness will make him wag his tail.

• Scratch a dog and you’ll find a permanent job.

• Money will buy a fine dog, but only kindness will make him wag his tail.

Gas LawsGas Laws

Lesson 3Lesson 3

Avogadro's Principle Avogadro's Principle

• States that equal volumes of gases at the same temperature and pressure contain equal number of particles.

• States that equal volumes of gases at the same temperature and pressure contain equal number of particles.

Crystal lattice Crystal lattice

• A well - defined, three -dimensional arrangement, repeated throughout the solid.

• A well - defined, three -dimensional arrangement, repeated throughout the solid.

Liquid crystal Liquid crystal

• When a solid melts, its crystal lattices disintegrate and its particles lose their three-dimensional pattern.

• When a solid melts, its crystal lattices disintegrate and its particles lose their three-dimensional pattern.

Equivalent PressuresEquivalent Pressures

1 atm 760 Hg 760 Torr 14.7 psi 101.3 kpa1 atm 760 Hg 760 Torr 14.7 psi 101.3 kpa

Problem 1Problem 1

• How many atm are in 856 torr?

• Answer• 1.13 atm

• How many atm are in 856 torr?

• Answer• 1.13 atm

Problem 2Problem 2

• How many Pa are in 16.4 atm?

• Answer• 1661320 Pa or 1.66 x 106 Pa

• How many Pa are in 16.4 atm?

• Answer• 1661320 Pa or 1.66 x 106 Pa

Viscosity Viscosity

• The stronger the intermolecular forces, the higher is the viscosity.

• Viscosity also increases with the mass of a liquid’s particles and the length of molecule chains.

• A measure of the resistance of a liquid to flow is called viscosity.

Amorphous SolidsAmorphous Solids• Examples of amorphous solids

include glass, rubber, cotton candies, slime, and many plastics.

Melting PointMelting Point

• Temperature of the solid when its crystal lattice begins to disintegrate.

• Temperature of the solid when its crystal lattice begins to disintegrate.

Freezing point Freezing point

• Temperature of a liquid when it begins to form a crystal lattice and becomes a solid.

• Temperature of a liquid when it begins to form a crystal lattice and becomes a solid.

Boiling PointBoiling Point

• Temperature of the substance when its vapor pressure equals the pressure exerted on the surface of the liquid.

• (For liquids in an open container, the pressure exerted equals atmospheric pressure.)

• Is affected by change in pressure.

• Temperature of the substance when its vapor pressure equals the pressure exerted on the surface of the liquid.

• (For liquids in an open container, the pressure exerted equals atmospheric pressure.)

• Is affected by change in pressure.

SublimationSublimation• Process by which particles of a solid

escape from its surface and form a gas.

Ex: CO2 and

clothes on a clothes line duringfreezing temps.

• Process by which particles of a solid escape from its surface and form a gas.

Ex: CO2 and

clothes on a clothes line duringfreezing temps.

Condensation Condensation

• The process by which a gas or vapor becomes a liquid. It is the reverse of vaporization.

• Ex: Dew

• The process by which a gas or vapor becomes a liquid. It is the reverse of vaporization.

• Ex: Dew

Vapor PressureVapor Pressure

• Is the pressure exerted by a vapor over a liquid.

• Is the pressure exerted by a vapor over a liquid.

Air Air

• Air is made up of four main gases: N2, O2, Ar, and CO2.

• Air is made up of four main gases: N2, O2, Ar, and CO2.

Pressure B-ballPressure B-ball

Problem 3Problem 3

• The basketball was slightly deflated and has a volume of 17cm3 at 1.7 atm. Joe begins to air it up and he pumps it until there is a pressure of 2.5 atm. What is the new volume?

• The basketball was slightly deflated and has a volume of 17cm3 at 1.7 atm. Joe begins to air it up and he pumps it until there is a pressure of 2.5 atm. What is the new volume?

WorkWork

• P1 x V1 = P2 x V2

• 17 cm3 x 1.7 atm = V2 x 2.5 atm

• Answer = 11.56 cm3

• P1 x V1 = P2 x V2

• 17 cm3 x 1.7 atm = V2 x 2.5 atm

• Answer = 11.56 cm3

Problem 4Problem 4

• The reading of a tire-pressure gauge is 35 psi. What is the equivalent pressure in kilopascals?

• The reading of a tire-pressure gauge is 35 psi. What is the equivalent pressure in kilopascals?

WorkWork

• Answer• Answer

Problem 5Problem 5

• What pressure in atmospheres will 18.6 mol of methane exert when it is compressed in a 12.00-L tank at a temperature of 45°C?

• What pressure in atmospheres will 18.6 mol of methane exert when it is compressed in a 12.00-L tank at a temperature of 45°C?

WorkWork

Problem 6Problem 6

• A sample of nitrogen monoxide has a volume of 72.6 mL at a temperature of 16°C and a pressure of 104.1 kPa. What volume will the sample occupy at 24°C and 99.3 kPa?

• A sample of nitrogen monoxide has a volume of 72.6 mL at a temperature of 16°C and a pressure of 104.1 kPa. What volume will the sample occupy at 24°C and 99.3 kPa?

WorkWork

• P1 x V1 = P2 x V2

T1 T2

Answer78.22 ml

• P1 x V1 = P2 x V2

T1 T2

Answer78.22 ml