Gas Graphing and Collecting Gases over Water Problems 1. Sketch a graph that shows the relationship of pressure and volume in gases. 2. Sketch a graph that shows the relationship of temperature and pressure in gases. 3. Hydrogen produced in the following reaction is collected over water at 23 oC (vapor pressure = 2.81 kPa) when the barometric pressure is 98.9 kPa: 2 Al (s) + 6 HCl (aq) 2 AlCl3 (aq) + 3 H2 (g) What volume of the “wet” gas will be collected in the reaction of 1.50 g Al with excess HCl? 4. Hydrogen gas is collected over water at 18 oC (vapor pressure = 2.07 kPa). The total pressure inside the collection jar is set at the barometric pressure of 98.4 kPa. If the volume of the gas is 246 cm 3, what mass of hydrogen is collected? 5. A sample of KClO3 was heated to decompose it to potassium chloride and oxygen. The oxygen was collected over water at 21 oC (water vapor = 2.49 kPa) and a barometric pressure of 99.5 kPa. A 155-cm3 volume of the gaseous mixture was obtained. What mass of KClO3 was decomposed? 6. A sample of gas was collected over water at 25 oC (vapor pressure = 3.17 kPa) with barometric pressure at 100.3 kPa and a volume of 85.0 cm3. The container that the gas came from was 36.82 g before the sample was collected and 36.56 g afterwards. What is the molar mass of the gas?