Properties of Matter

1
Properties of Matter

• Gas Behaviors and Laws

2
Gases

• Gases behave differently than solids or liquids.
• Unlike the particles that make up solids and
  liquids, gas particles have a large amount of
  empty space between them.
• The space that gas particles occupy is the gass
  volume, which can change because of temperature
  and pressure.
• http//www.chemistry.ohio-state.edu/betha/nealGasL
  aw/fr1.1.html
• http//www.chemistry.ohio-state.edu/betha/nealGasL
  aw/fr1.2.html

3
Gas-Temperature

• Temperature is a measure of how fast the
  particles in an object are moving.
• The faster the particles are moving, the more
  energy they have.
• Therefore, the gas is expanding.
• The slower the particles are moving, the less
  energy they have.

4
Gas- Volume

• Volume is the amount of space that an object
  takes up.
• Since the particles of a gas spread out, the
  volume of any gas depends on the container that
  the gas is in.
• Example, inflated balloons that are twisted into
  different shapes. Shaping the balloons was
  possible because particles of gas can be
  compressed, or squeezed together into a smaller
  volume.

5
Gas- Pressure

• Pressure is the amount of force exerted on a
  given area of surface.
• Another way to think of pressure is to think of
  it as the number of times the particles of a gas
  hit the inside of their container.
• When more particles hit the inside surface of a
  basketball, the force on the inside surface of
  the ball increases. This increased force leads to
  greater pressure, which makes the basketball feel
  harder than a beach ball.

6
Gas Behavior Laws

• Scientists have found that the temperature,
  volume, and pressure of a gas are linked.
• Changing one of the factors changes the other two
  factors.
• The relationship between temperature, volume, and
  pressure are described by gas laws.

7
Gas Laws

• Imagine that a diver 10m below the surface of a
  lake blows a bubble of air. When the bubble
  reaches the surface, the bubbles volume has
  doubled.
• The difference in pressure between the surface
  and 10m below the surface caused this change.

8
Gas Laws

• The relationship between the volume and pressure
  of a gas was first described by Robert Boyle
  (1627-1691).
• Boyles Law- the volume of a gas is inversely
  proportional to the pressure of a gas when
  temperature is constant.
• As the pressure increases the volume decreases
  (at constant temperature).

9
Gas Laws

• If you blow air into a balloon and leave it in
  the hot sun, the balloon might pop!
• Jacques Charles (1742-1823) created Charles Law.
• Charles Law- the volume of a gas is directly
  proportional to the temperature of a gas when
  pressure is constant.
• If the temperature increases the volume also
  increases (at constant pressure).