Bevior of Gases

Behavior of Gases

• Glossary

  • Force: Force per unit area.

  • Mole: A unit for the amount of substance.

  • Pressure: Force per unit area (Pa).

• Kinetic Molecular Theory

  • States that gas particles:

  • Don’t attract or interact with each other.

  • Have negligible size; gas volume is mostly empty space.

  • Average kinetic energy depends on temperature.

  • No gas is ideal, as real gases differ from theoretical assumptions.

• Pressure of Gases

  • SI unit for pressure: Pascal (Pa).

  • Atmospheric pressure at sea level: 1 atm = 101.325 kPa = 14.7 psi.

• Temperature of Gases

  • Absolute zero: 0 K = -273.15 °C.

  • Conversion:

  • K = °C + 273.15

• Standard Temperature and Pressure (STP)

  • Used for chemistry experiments:

  • Temperature: 0 °C (273.15 K)

  • Pressure: 1 atm (101.325 kPa).

• Gas Behavior

  • Higher temperatures = more energy.

Gas Laws

• Boyle's Law

  • States volume and pressure are inversely proportional at constant temperature:

  • P1 V1 = P2 V2

  • Example calculation demonstrates concept.

• Charles's Law

  • States volume is directly proportional to temperature at constant pressure:

  • \frac{V1}{T1} = \frac{V2}{T2}

  • Example calculation demonstrates concept.

• Avogadro’s Law

  • Volume of gas is proportional to the number of moles at constant temperature and pressure:

  • \frac{V1}{n1} = \frac{V2}{n2}

  • Example calculation demonstrates concept.

• Volume of Gas at STP

  • 1 mole of gas occupies 22.4 L at STP.