What is the molecular weight of a gas if 2.21 g of the gas occupies a volume of 1.72 L at 25.0 °C and 780. mmHg?

A mixture of xenon and neon gases is maintained in a 8.93 L flask at a temperature of 56°C. If the partial pressure of xenon is 0.456 atm and the partial pressure of neon is 0.277 atm, the total pressure in the flask is  atm.

Boron trifluoride gas is collected at 6.0 °C in an evacuated flask with a measured volume of 15.0 L. When all the gas has been collected, the pressure in the flask is measured to be 0.140 atm . Calculate the mass and number of moles of boron trifluoride gas that were collected. Be sure your answer has the correct number of significant digits. mass: g x10 mole: | mol ?

The Haber Process synthesizes ammonia at elevated temperatures and pressures. Suppose you combine 1580 L of nitrogen gas and 4240 L of hydrogen gas at STP, heat the mixture to run the reaction, then separate the ammonia from the reaction mixture. What volume of reactant, measured at STP, is left over? Assume the reaction goes to completion. N₂ (g) + 3 H₂ (g) → 2 NH₃ (g)