Chemistry
posted by E on .
1. A cylinder of Xenon has a volume of 750. ml. At 25.0°C the cylinder has a pressure of 655 torr. How much Argon is present in the cylinder?
a. 240. moles
b. 0.0264 moles
c. .315 moles
d. 26.5 moles
2.If a 25 liter cylinder of gaseous ammonia at atmospheric pressure (1.0 atm) is heated from 50°C to 450°C, what is the final pressure?
a. 9.0 atm
b. 0.11 atm
c. 0.45 atm
d. 2.2 atm
3.What are the relative rates of effusion of molecular hydrogen and molecular oxygen?
a. 2
b. 0.5
c. 4
d. 1
4.An unknown gas has a molecular weight of 30.07 g/mol. What is the density of the gas at STP?
a. 1.3 x 103 g/cm3
b. .0385 g/cm3
c. 1.5 g/cm3
d. 3.1 x 104 g/cm3

a. Use pV = nRT and solve for n= number of moles.
Then moles = g/molar mass. Solve for grams.