6-5 Apply Dalton's Law of partial pressures

6-5-1. Hydrogen gas is collected over water at 25^oC. The vapor pressure of water at this temperature is 23.8 Torr. If the total pressure of the gas is 755.0 Torr, what is the partial pressure of hydrogen?
A. 731.2 Torr, B. 778.8 Torr, C. 23.8 Torr, D. None of the above

6-5-2. A 5.0 mg sample of gas "X" is found to have a pressure of 0.100 atm at 298K in a given container. A 10.0 mg sample of gas "Y," placed in the same container is found to have a pressure of 0.150 atm at 298K. What would be the total pressure of a mixture of 5.0 mg "X" and 10.0 mg "Y" in the same container at 298K? (assume no reaction)
A. 0.050 atm, B. 0.105 atm, C. 0.250 atm, D. 2.0 atm

6-5-3. A mixture containing 0.200 mol H₂ and 0.300 mol N₂ has a total pressure of 720.0 Torr. What is the partial pressure of H₂ in the mixture?
A. 144 Torr, B. 216 Torr, C. 288 Torr, D. 360 Torr