The mass of a particular gas is 3.562 g. If the temperature of the gas in a 126.4 mL vessel is 97.6oC, and the atmospheric pressure is 752.5 mmHg, what is the molar mass of the gas?
If we assume that the gas is an ideal gas then 1 mole of the gas will occupy 22.4 litres at STP. It we calculate the volume that the gas occupies at STP then the we can calculate the number of moles from
number of moles = volume at STP/22.4 L mol^-1
Use V1=P2V2T1/T2P1 to calculate the volume
where P2 = 752.5 mm Hg
P1=760 mm Hg
T1=273.15 K
T2=(273.15 + 97.6)K
V2=0.1264 L
once you have the number of moles the MM is
MM = 3.563 g /number of moles