A sample of gas weighs 2.832g and has a volume of 1010.0 ML at 775.0 torr and 31.0 degrees Celsius what is its molar mass?
PV = nRT. Solve for n = moles. Don't forget T must be in kelvin, V in L and P in atm.
Then n = grams/molar mass. You hae grams and n, solve or molar mass.