Question

Part A). A gas mixture with a total pressure of 750 mmHgcontains each of the following gases at the indicated partial pressures: 133 mmHg CO2, 221 mmHg Ar, and 181 mmHg O2. The mixture also contains helium gas. What mass of helium gas is present in a 10.8-Lsample of this mixture at 279 K ? Express your answer in grams.

Part B) A heliox deep-sea diving mixture contains 2.0 g of oxygen to every 98.0 g of helium. What is the partial pressure of oxygen when this mixture is delivered at a total pressure of 7.5 atm ? Express your answer using two significant figures.

Part C) Oxygen gas reacts with powdered aluminum according to the following reaction: 4Al(s)+3O2(g)→2Al2O3(s) What volume of O2 gas, measured at 772 mmHgand 16 ∘C, is required to completely react with 55.0 g of Al? Express the volume in liters to three significant figures.

Part D) Consider the following chemical reaction: 2H2O(l)→2H2(g)+O2(g) What mass of H2O is required to form 1.6 L of O2at a temperature of 300 K and a pressure of 0.990 atm ? Express your answer using two significant figures.