G AS L AWS & S TATES OF M ATTER By Klaus and Pat

C OMBINED G AS L AW Describes the relationship among the pressure, temperature, and volume of an enclosed gas. Allows you to do calculations for situations in which only the amount of gas is constant. (P 1 x V 1 ) / T 1 = (P 2 x V 2 ) / T 2

C OMBINED G AS L AW E XAMPLES If I initially have a gas at a pressure of 12 atm, a volume of 23 liters, and a temperature of 200 K, and then I raise the pressure to 14 atm and increase the temperature to 300 K, what is the new volume of the gas?

I DEAL G AS L AW To calculate the number of moles of a contained gas requires an expression that contains the variable n. PV = nRT R=.0821 atm R= 8.31 kpa

I DEAL G AS L AW E XAMPLES If I have 4 moles of a gas at a pressure of 5.6 atm and a volume of 12 liters, what is the temperature?

B OYLE ’ S L AW For a given mass of gas at a given temperature, the volume of the gas varies inversely with pressure P (1) x V (1) = P (2) x V (2)

B OYLE ’ S L AW E XAMPLES A 175 mL sample of neon had its pressure changed from 75 kPa to 150 kPa. What is its new volume?

C HARLES ’ L AW States that the volume of a fixed mass of gas is directly proportional to its Kelvin temperature if the pressure is kept constant. V (1) / T (1) = V (2) / T (2) The ratio of V(1) / T(1) is equal to the ratio V(2) / T(2) because the ratio is constant to all conditions of temperature.

C HARLES ’ L AW E XAMPLES A sample of nitrogen occupies a volume of 250 mL at 25 o C. What volume will it occupy at 95 o C?

K INETIC E NERGY Particles in constant motion and random movement Can explain other properties of gas like their ability to expand and take the shape and volume of their containers.

P ARTICLE M OVEMENT Particles move along in straight-line paths until they collide with other particles or the walls of their containers. The motion of particles is constant and random. Particles in gas move freely because there is no significant forces of attraction or repulsion.