Gas Laws Introduction to Gas Laws Key Terms

Gas Laws! Introduction to Gas Laws.

Key Terms Pressure: the amount of force per unit area of surface Newton: the SI unit force Pascal: the SI unit of pressure

Properties of Gases have unique properties because the distance between particles is much greater than solids or liquids! Gases expand to fill any container. Gases are fluids, as they are able to flow Gases have lower densities than solids or liquids. Most of the volume occupied by a gas is empty space, as the molecules are further apart.

Properties Continued. Although gases have lower densities compared to solids and liquids, they can be more or less dense than one another. Gases are highly compressible. No volume equates to a lot of empty space! Compressing gas particles moves them closer together.

Air Pressure Collisions with gas molecules and with the surface of the earth cause air pressure. Less dense gases are at higher altitudes. Less dense air exerts less pressure, as their molecules collide less often. Your ears pop when you are in an airplane, as the air inside your ears changes to match the same pressure as the outside air.

Kinetic Molecular Theory Model used to predict gas behavior. States: Gas particles are in constant, random motion Gas particles a far apart relative to their size *fluidity, compressibility* Pressure exerted by a gas is a result of collisions of the molecules against the walls of their container.

Pressure n. Which shoes create the most pressure?

Measuring Pressure Barometer measures atmospheric pressure. The column falls until the pressure exerted by its weight equals the atmospheric pressure. n. Mercury Barometer

Pressure Units KEY UNITS AT SEA LEVEL 101. 325 k. Pa (kilopascal) 1 atm 760 mm Hg 760 torr 14. 7 psi

Converting Pressure Units - Practice Carbon dioxide has a pressure of 72. 7 atm. What is this value in pascals? The vapor pressure of water at 50ºC is 12. 33 k. Pa. What is this value in mm Hg? Convert 100 k. Pa to atmospheres. A tire is inflated to a 44. 7 psi. Calculate the total pressure in pascals.

Standard Temperature and Pressure At sea level, the atmosphere keeps mercury in a barometer at 760 mm. Hg or 1 atmosphere. Standard Temperature & Pressure : 0ºC and 1 atmosphere (atm)