Halothane is a gas once used in anesthesia in hospitals. Its density is 0.857 g/L at 23 ºC and 80.2 torr. What would be its density at STP? What is its molar mass?
P*molar mass = density*RT
Substitute and solve for molar mass. Remember P = 80.2/760 and T = (273+23)K
Then density at STP is molar mass/22.4 = ? g/L.