Ideal Gas Law (Equation): P = Pressure PV = nRT V = Volume n = number of moles R = ideal gas constant T = Temperature (K)
R = PV = (1 atm )(22.4 L) R = 0.0821 L * atm We can calculate R by looking at 1 mol of a gas at STP: STP = 273 K and 1 atm @ STP, 1 mol of a gas occupies 22.4 L R = PV = (1 atm )(22.4 L) nT (1 mol)(273 K) R = 0.0821 L * atm mol * K
Use ideal gas law, PV=nRT. Practice Problem A 23.8-L cylinder contains oxygen gas at 20.0 0C and 732 torr. How many moles of oxygen are in the cylinder? PV = n RT Use ideal gas law, PV=nRT. Pressure must be in atm, Temperature in K: 732 torr x 1 atm = 0.963 atm 760 torr (0.963 atm)(23.8 L) = n (0.0821 L atm/mole K)(293 K ) = 0.953 mol
Do Problems: 20, 22, & 24 pg 453 26-29 pg 455