gas density and dalton's law 2

1.A mixture of Oxygen and nitrogen contains oxygen at a pressure of 436 torr and nitrogen at a pressure of 378 torr. What is the pressure of the mixture?




2. A 5.00 L scuba tank contains 1.05 mol of oxygen and 0.418 mol of helium at 25°C. What is the partial pressure of each gas and what is the total pressure in the tank?




3.What would be the total pressure in torr of a mixture prepared by adding 20.0 mL of N2 at 0° C and 740 torr plus 30.0 mL of O2 at 0° C and 640 torr to 50.0 mL container at 0° C?




4.A student collects O2 gas at 25°C until the levels of water inside and outside are equal. If the volume of the gas is 245 mL and the atmospheric pressure is 758 torr, what is the pressure of O2 gas in the wet mixture at 25°C? What will be the volume in liters of dry oxygen at STP? (Hint: look for vapor pressure of water at 25°C in table)




5.Oxygen gas was collected over water at 22°C. The mixture of oxygen and water had a total pressure of 754 torr and a volume of 0.650 L. Calculate the partial pressure of oxygen and number of moles of oxygen. The vapor pressure of water is 21 torr at 22°C.