Molar Mass of a Gas- Cat Reference to follow: MM = DRT/P D = density n g/L The density of a gas was.

Molar Mass of a Gas- Cat Reference to follow: MM = DRT/P D = density n g/L The density of a gas was measured at 1.50 atm and 27 degree C and found to be 1.95 g/L. Calculate the molar mass of the gas. Daltons’s Law of Partial Pressure- For a mixture of gases in a container the total pressure exerted is the sum of the pressures that each gas would exert if it were alone, P_total = P_1 + P_2 + P_3 … P_total = n_1RT/V + n_2RT/V + n_3RT/V Therefore N_total = RT/V Mixtures of helium and oxygen are used in scuba diving tanks to help prevent “the bends.” For a particular dive, 46 L He at 25 degree

Molar Mass of a Gas- Cat Reference to follow: MM = DRT/P D = density n g/L The density of a gas was measured at 1.50 atm and 27 degree C and found to be 1.95 g/L. Calculate the molar mass of the gas. Daltons’s Law of Partial Pressure- For a mixture of gases in a container the total pressure exerted is the sum of the pressures that each gas would exert if it were alone, P_total = P_1 + P_2 + P_3 … P_total = n_1RT/V + n_2RT/V + n_3RT/V Therefore N_total = RT/V Mixtures of helium and oxygen are used in scuba diving tanks to help prevent “the bends.” For a particular dive, 46 L He at 25 degree C and 1.0 atm and 12 L O_2 at 25 degree C and 1.0 atm were pumped into a tank with a volume of 5.0 L. Calculate the partial pressure of each gas and the total pressure in the tank at 25 degree C. Mole Fraction – the ratio of the number of moles of a given component in a mixture to the total number of moles in the mixture. A. Mole Fraction of C in CO_2 C = 1(12) # moles of C = 12 g X 1 mole/12 g = 1 mole C X = 1 mole = .333 (1 mole + 2 mole) O = 2(16)/44 g # moles of O = 32 g X 1 mole/16 g = 2 moles O B. With some whiz bang algebra (check this out in the book) it can be shown that the mole fraction of each component in a mixture of ideal gases is directly related to its partial pressure. X_1 = n_1/N_total = P_1/P_total P_1 = X_1 X P_total