IDEAL GAS LAW

What’s the Diff?! What is the difference between a real gas and an ideal gas?! Google it! Or read page 172 in your textbook!

Ideal Gas Molecules size is negligable Gas molecules are in constant, random, stratight line motion because… …no force exist between them Gas molecules undergo perfectly elastic collisions, where no energy is lost, collisions happen quickly

Real Gas In high pressures molecules are forced together and so the size is greater than the space between the molecules As temp decreases, molecules slow down and may eventually stick together and become liquid Molecules aer more like soft spheres and can change shape durig a collision and rebound making this process a little slower

Boyle’s Law = volume of gas is inversely proportional to the pressure Charles’ Law = the volume of a gas is directly proportional to the absolute temperature Avogadro’s theory = the volume of a gas is directly proportional to the chemical amount of matter

Ideal Gas Law PV = nRT

The ideal gas law is a combination of Charles’ Law, Boyles’ Law and Avogadro’s Hypothesis

Boyle’s Law = PV = a constant Charles’ Law = P/T = a constant Avogadro’s theory = V/n = a constant

All together now PV = R (universal gas constant) nT R = 8.31 L kPa / mol K

So… PV = nRT

Example: What is the volume of 3.35mol of neon at 42.5 degrees Celsius and 96.5kPa? List your knownsList your unknowns T = 42.05C = 315.5KV = ???? R = 8.31LkPa/molK n = 3.35mol P = 96.5kPa

PV = nRT V = nRT / P (rearranged to solve for unknown) V = 3.35mol x 8.31LkPa/molK x 315.5K 96.5kPa V = 91.0L

Example 2: What is the volume of 66.4g of CO2(g) at 32.0C and 115kPa? Knowns Unknowns g = 66.4gn = mols????? T = 32.0C = 305KV = ?????? P = 115kPa R = 8.31LkPa/molK

Example 3 What is the molar mass of 3.827g of gas at a temperature of 25C, 11.38L and 2.88atm?