Characteristics of Gases 12.1
Gases are FLUIDS
- Fluid because they can flow.
Gases have low density
- Long distance between particles
- Gas particles have to travel a long distance before they collide with each other.
Gases are compressible
- Gas particles can be moved closer together with PRESSURE.
- Increased pressure = decreased volume
- Decreased pressure = increased volume
A gas will completely fill its container.
- Gas particles are constantly moving.
- Gas particles do not attract each other.
- Collisions of gas molecules cause air pressure.
- Atmospheric pressure = the weight of the air above you.
- Higher up = less air above = less pressure
- SI unit for force = newton (N)
- SI unit for pressure = pascal (Pa)
- Atmospheric pressure is measured with a barometer.
- Standard Temperature and Pressure = 0 0 C and 1 atm.
- Avagadro came up with this to compare gases.
- 1. Gas particles are in constant, rapid motion.
- 2. Gas particles are far apart.
- 4. Gases can be compressed.
- Pressure can be measured in several units.
- psi, torr, pascals, N/m 2 , inches of Hg, mm Hg
- All of the units can be converted to each other.
- The conversion works just like MOL ISLAND.