States of MatterStates of MatterChap. 13Chap. 13Chap. 13Chap. 13

State of matter in which particles are separated by large distances.

I.I. GasesGases

I.I. GasesGasesA.A. Gas propertiesGas properties

I.I. GasesGasesA.A. Gas propertiesGas properties

1.1. Gases have massGases have mass

I.I. GasesGasesA.A. Gas propertiesGas properties

1.1. Gases have massGases have mass

2.2. Gases occupy spaceGases occupy space

I.I. GasesGasesA.A. Gas propertiesGas properties

1.1. Gases have massGases have mass

2.2. Gases occupy spaceGases occupy space

3.3. Gases completely fill their Gases completely fill their containerscontainers

I.I. GasesGasesA.A. Gas propertiesGas properties

1.1. Gases have massGases have mass

2.2. Gases occupy spaceGases occupy space

3.3. Gases completely fill their Gases completely fill their containerscontainers

4.4. Gases have low densityGases have low density

I.I. GasesGasesA.A. Gas propertiesGas properties

5.5. Gases can be compressed & Gases can be compressed & expandedexpanded

I.I. GasesGasesA.A. Gas propertiesGas properties

5.5. Gases can be compressed & Gases can be compressed & expandedexpanded

6.6. Gases exert pressureGases exert pressure

I.I. GasesGasesA.A. Gas propertiesGas properties

5.5. Gases can be compressed & Gases can be compressed & expandedexpanded

6.6. Gases exert pressureGases exert pressure

7.7. Gases diffuse & effuseGases diffuse & effuse

I.I. GasesGasesB.B. The Kinetic Molecular The Kinetic Molecular

Theory (KMT)Theory (KMT)

An explanation of why gases behave the way they do.

I.I. GasesGasesB.B. The Kinetic Molecular The Kinetic Molecular

Theory (KMT)Theory (KMT)1.1. Gases consist of tiny Gases consist of tiny

particlesparticles in constant motion in constant motion

I.I. GasesGasesB.B. The Kinetic Molecular The Kinetic Molecular

Theory (KMT)Theory (KMT)1.1. Gases consist of tiny Gases consist of tiny

particlesparticles in constant motion in constant motion

2.2. Gas particles travel in Gas particles travel in straight line until they straight line until they collidecollide with other particles with other particles or the containeror the container

I.I. GasesGasesB.B. The Kinetic Molecular The Kinetic Molecular

Theory (KMT)Theory (KMT)3.3. Gas particles are separated Gas particles are separated

by relatively by relatively largelarge spaces spaces

I.I. GasesGasesB.B. The Kinetic Molecular The Kinetic Molecular

Theory (KMT)Theory (KMT)3.3. Gas particles are separated Gas particles are separated

by relatively by relatively largelarge spaces spaces

4.4. The kinetic energy of gas The kinetic energy of gas particles depends on the particles depends on the temperaturetemperature

KE = ½ mv2

I.I. GasesGasesC.C. DiffusionDiffusion

Spreading out of particles (high to low concentration)

I.I. GasesGasesC.C. DiffusionDiffusion

1.1. Diffusion depends on how Diffusion depends on how fast particles travel.fast particles travel.

I.I. GasesGasesC.C. DiffusionDiffusion

1.1. Diffusion depends on how Diffusion depends on how fast particles travel.fast particles travel.a.a. Cold particles travel _____ Cold particles travel _____

than warm particles.than warm particles.

I.I. GasesGasesC.C. DiffusionDiffusion

1.1. Diffusion depends on how Diffusion depends on how fast particles travel.fast particles travel.a.a. Cold particles travel Cold particles travel slowerslower

than warm particles.than warm particles.

b.b. Small particles travel _____ Small particles travel _____ than small particles.than small particles.

I.I. GasesGasesC.C. DiffusionDiffusion

1.1. Diffusion depends on how Diffusion depends on how fast particles travel.fast particles travel.a.a. Cold particles travel Cold particles travel slowerslower

than warm particles.than warm particles.

b.b. Small particles travel Small particles travel fasterfaster than small particles.than small particles.

I.I. GasesGasesC.C. DiffusionDiffusion

1.1. Diffusion depends on how Diffusion depends on how fast particles travel.fast particles travel.

2.2. Graham found that the Graham found that the diffusion rate was inversely diffusion rate was inversely proportional to the square proportional to the square root of the molar mass.root of the molar mass.

Graham’s LawGraham’s Law

RateRateAA

√RateRateBB

==Molar mass Molar mass BB

Molar mass Molar mass AA

II.II. Measuring GasesMeasuring GasesA.A. Gas PressureGas Pressure

II.II. Measuring GasesMeasuring GasesA.A. Gas PressureGas Pressure

1.1. Pressure is force per areaPressure is force per area

P = F/A

II.II. Measuring GasesMeasuring GasesA.A. Gas PressureGas Pressure

1.1. Pressure is force per areaPressure is force per area

2.2. The atmosphere exerts The atmosphere exerts pressurepressure

II.II. Measuring GasesMeasuring GasesA.A. Gas PressureGas Pressure

1.1. Pressure is force per areaPressure is force per area

2.2. The atmosphere exerts The atmosphere exerts pressurepressure

3.3. Pressure unitsPressure units

Equivalent Pressure units

1.00 atmosphere (atm)1.00 atmosphere (atm)101325 pascals (Pa)101325 pascals (Pa)

101.325 kilopascals (kPa)101.325 kilopascals (kPa)760 __________ (mm Hg)760 __________ (mm Hg)

760 torricelli (torr)760 torricelli (torr)14.7 pounds per square inch (___)14.7 pounds per square inch (___)

II.II. Measuring GasesMeasuring GasesA.A. Gas PressureGas Pressure

1.1. Pressure is force per areaPressure is force per area

2.2. The atmosphere exerts The atmosphere exerts pressurepressure

3.3. Pressure unitsPressure units

4.4. Converting pressureConverting pressure

Self Check – Ex. 1Self Check – Ex. 1

A container of gas has a A container of gas has a pressure of 50 atm. What is pressure of 50 atm. What is this pressure in psi?this pressure in psi?

Self Check – Ex. 2Self Check – Ex. 2

What is the pressure in What is the pressure in pascals of a gas sample that pascals of a gas sample that is 140 kPa?is 140 kPa?

II.II. Measuring GasesMeasuring GasesB.B. InstrumentsInstruments

II.II. Measuring GasesMeasuring GasesB.B. InstrumentsInstruments

1.1. BarometerBarometer

Measures atmospheric pressure.

II.II. Measuring GasesMeasuring GasesB.B. InstrumentsInstruments

1.1. BarometerBarometer

Atmosphere ‘holds up’ a column of mercury

a.a. MercuryMercury

Image: Dr. Leon L. Combs

II.II. Measuring GasesMeasuring GasesB.B. InstrumentsInstruments

1.1. BarometerBarometera.a. MercuryMercury

b.b. AneroidAneroid

Name means ‘without liquid’Image: Australian BOM

II.II. Measuring GasesMeasuring GasesB.B. InstrumentsInstruments

1.1. BarometerBarometer

2.2. ManometerManometer

Measures pressure of an enclosed gas

22 mm

Hg

CO2

II.II. Measuring GasesMeasuring GasesB.B. InstrumentsInstruments

1.1. BarometerBarometer

2.2. ManometerManometer

3.3. Example calculationsExample calculations

Self Check – Ex. 3Self Check – Ex. 3

What is the pressure of the What is the pressure of the COCO22 gas pictured below? gas pictured below?

Atmospheric pressure is Atmospheric pressure is 755 mmHg.755 mmHg.

22 mm

Hg

CO2

Self Check – Ex. 4Self Check – Ex. 4

What is the pressure of the What is the pressure of the helium gas pictured helium gas pictured below? Atmospheric below? Atmospheric pressure is 1.1 atm.pressure is 1.1 atm.

65 mm

Hg

He

The End