The Gaseous State Chapter 10 Kinetic Theory Kinetic

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The Gaseous State Chapter 10

The Gaseous State Chapter 10

Kinetic Theory • Kinetic energy is the NRG of motion • The Kinetic Theory

Kinetic Theory • Kinetic energy is the NRG of motion • The Kinetic Theory states that all particles of matter are in constant motion

Assumptions of Kinetic Theory in relation to gases: 1. Gases are composed of small,

Assumptions of Kinetic Theory in relation to gases: 1. Gases are composed of small, hard spheres with an insignificant volume 2. They are far apart with empty space in between

3. There are no attractive or repulsive forces between the particles 4. The particles

3. There are no attractive or repulsive forces between the particles 4. The particles move rapidly and are in constant motion 5. They travel in straight paths independently of each other

6. Gases fill their container indefinitely (they will expand) 7. Only change direction after

6. Gases fill their container indefinitely (they will expand) 7. Only change direction after colliding with something else 8. All collisions are perfectly elastic – no energy loss

 • The kinetic theory is helpful in explaining gas pressure • Gas pressure:

• The kinetic theory is helpful in explaining gas pressure • Gas pressure: force exerted by a gas on its container • An empty space with no particles = vacuum = no pressure

 • Atmospheric pressure – the pressure of air around earth – dependent on

• Atmospheric pressure – the pressure of air around earth – dependent on the weather • Barometers measure air pressure

 • SI Unit of pressure is the pascal (Pa) • At sea level,

• SI Unit of pressure is the pascal (Pa) • At sea level, Atm. Pressure is 101. 3 kilopascals (k. Pa) • mm. Hg and atmospheres (atm) are older units of pressure • 1 atm = 760 mm. Hg = 101. 3 k. Pa

 • The standard conditions to relate measured values to are o 1 atm

• The standard conditions to relate measured values to are o 1 atm (101. 3 k. Pa) and 0 C, or STP – this is important when discussing gases and gas pressure

 • When a substance is heated, the particles store some of the absorbed

• When a substance is heated, the particles store some of the absorbed NRG (potential) but the NRG not stored increases the speed of the particles, the average kinetic NRG & the temperature

 • The actual particles have a wide range of kinetic energies – but

• The actual particles have a wide range of kinetic energies – but temperature is the average kinetic energy • At high temperatures, there is a wider range of kinetic NRGs

 • As a substance cools, the particles lose energy & slow down o

• As a substance cools, the particles lose energy & slow down o • Absolute Zero (0 K, -273 C) theoretical temperature when no movement occurs = no NRG

 • Check out this website tutorial on the States of Matter, from CHEMTUTOR.

• Check out this website tutorial on the States of Matter, from CHEMTUTOR. com Click HERE for Tutorial

 • Now, move on to the Phase Changes Power Point Click Here to

• Now, move on to the Phase Changes Power Point Click Here to go on to the Phase Changes Power Point