Kinetic Theory & Gas Laws October 2014

Kinetic Theory of Matter Kinetic Theory of Matter: all matter is made of tiny particles (atoms) which are in constant motion

Fluid Behavior Fluids: any substance in which the particles are free to flow. (move past one another.) (Gases and Liquids) All fluids exert pressure. (examples: water pressure, atmospheric pressure, blood pressure) The pressure of all fluids increases with depth. (More matter on top as you descend)

Pressure Pressure: The amount of force applied over a given area. The SI unit of pressure is the Pascal, (Pa).  One Pascal (Pa) is the force of 1 Newton exerted over an area of one square meter. 1 Pa = 1Newton = 1N 1Meter 2 m2 The English units for pressure are Pounds Inches 2 Pounds per squared inch, (PSI) http://www.youtube.com/watch?v=1FtLUdozmfA&feature=related (Head rush Balloon/Nails)   http://www.youtube.com/watch?v=P1zfktn4AzU&feature=related (Ellen show) http://www.youtube.com/watch?v=1FtLUdozmfA&feature=related (Head rush Balloon/Nails)   http://www.youtube.com/watch?v=P1zfktn4AzU&feature=related (Ellen show)

Pressure http://www.youtube.com/watch?v=1FtLUdozmfA&feature=related (Head rush Balloon/Nails)   http://www.youtube.com/watch?v=P1zfktn4AzU&feature=related (Ellen show)

Pressure and Altitude The higher the altitude, the lower the pressure, air particles are less densely packed together at higher altitudes. Air pressure decreases as altitude increases. 14,000 ft 9,000 ft 4,300 ft

Pressure Equilibrium Pressure Differentials: When pressures are unbalanced, energy flows from high pressure areas to low pressure areas until balanced. (Equilibrium is reached and there is no longer a difference.) Equilibrium: a state of balance

Properties of Gases No definite shape or volume, they expand to fill their container Particles move rapidly in all directions and constantly collide with each other and the walls of their container (creates pressure in container) Low density because particles are far apart (often used to fill tires or balloons) Gases are mostly empty space. Compressible

Gas Laws- Boyle’s Law Boyle’s law: (British; Robert Boyle) As the volume of a container of gas decreases, the pressure inside the container increases. (fixed amount of gas at a constant temperature) Volume ↓ then Pressure ↑ (the reverse is also true) V ↑ then P↓ This relationship is inversely proportional

Gas Laws- Boyle’s Law Examples of Boyle’s Law: Squeezing a closed balloon increases pressure inside, deep sea fish die when brought to the surface, air compressors, our diaphragms/lungs, etc… https://www.youtube.com/watch?v=27yqJ9vJ5kQ https://www.youtube.com/watch?v=27yqJ9vJ5kQ

Gas Laws- Boyle’s Law

Gas Laws- Charles’ Law Charles’ law: (French; Jacques Charles) The volume of a gas increases as the temperature increases. (Fixed amount of gas at a constant pressure) Temperature ↑ then Volume ↑ (the reverse is also true) T ↓ then V ↓ This relationship is directly proportional. https://www.youtube.com/watch?v=7JKVtbe-hV8 https://www.youtube.com/watch?v=GcCmalmLTiU https://www.youtube.com/watch?v=7JKVtbe-hV8 https://www.youtube.com/watch?v=GcCmalmLTiU

Gas Laws- Charles’ Law In theory, Charles could calculate the temperature at which volume would = zero. This temperature is called absolute zero. At absolute zero, all particle motion stops and the volume of the gas equals 0. Absolute zero = -273º C or 0 Kelvin. In reality: Gases can’t be cooled to a volume of zero. They condense into liquids when they are cooled below their boiling points or solidify when cooled below their melting point. Examples of Charles’ Law: hot air balloons, tires needing more gas in winter to be inflated fully, etc…

Gas Laws- Charles’ Law