A sample of argon gas occupies a volume of 6.57 L at 53.0°C and 0.880 atm. If it is desired to increase the volume of the gas sample to 8.20 L, while decreasing its pressure to 0.590 atm, the temperature of the gas sample at the new volume and pressure must be °C.

You have a gas, one of the three known phosphorus-fluorine compounds (PF3, PF3, and P2F4). To find out which, you have decided to measure its molar mass. (a) First, yon determine that the density of the gas is 5.60 g/L at a pressure of 0.971 atm and a temperature of 18.2 C. Calculate the molar mass and identify the compound. (b) To check the results from part (a), you decide to measure the molar mass based on the relative rales of effusion of the unknown gas and CO2. You find that CO2 effuses at a rate of 0.050 mol/min, whereas the unknown phosphorus fluoride effuses at a rate of 0.028 mol/min. Calculate the molar mass of the unknown gas based on these results.

93 The complete combustion of octane can be used as a model for the burning of gasoline: 2C8H18+25O216CO2+18H2O Assuming that this equation provides a reasonable model of the actual combustion process, what volume of air at 1.0 atm and 25°C must be taken into an engine to burn 1 gallon of gasoline? (The partial pressure of oxygen in air is 0.21 atm and the density of liquid octane is 0.70 g/mL.)

Given that a sample of air is made up of nitrogen, oxygen, and argon in the mole fractions 0.78 N2, 0.21 O2, and 0.010 Ar, what is the density of air at standard temperature and pressure?