Posted by Javier on .
Please!!! its extremely urgent. i do not need answers, only how to do it
A sample of nitrogen gas (N2) kept in a container of volume 10.1 L and at a temperature of 20.3°C exerts a pressure of 3.1 atm. Calculate the number of grams of gas present. Round to one decimal place, do not include units in your answer.
2) A volume of 0.194 L of a gas at STP weighs 0.545 g. Calculate the molar mass of the gas. Round to one decimal place do not include units.

Chemistry 
DrBob222,
1) Use PV = nRT and solve for n = moles N2. Then n = grams/molar mass, solve for grams.
2) Remember 1 mole of a gas at STP occupies 22.4L, use that to convert 0.194 L to moles. Then moles = grams/molar mass. You know moles and molar mass, solve for grams.