Name: ______________________________ Date: ___________________ Pd: ________ Unit 10 Sample Questions 1. Define pressure. 2. What is the Earth’s atmosphere? Describe its properties. 3. Define and Dalton’s Law of Partial Pressure. How is it useful? 4. Describe 3 methods for collecting gases from a reaction. When is it best to use a particular method over the other two? 5. Use the phase diagram below to complete: a. Identify areas A1-A3, lines L1-L3, points X1-X2, P1, and T3: X2 Pressure P1 L1→ A2 P2 L2 A1 A3 X1 L3 T1 T2 T3 Temperature b. c. d. e. f. g. h. i. If P2 = 1.00 atm, what are T1 and T2 in °C? In what phase(s) is a substance found on the line L2? What will happen to the substance if the pressure is substantially decreased while in area A1? What will happen to the substance if the temperature is substantially decreased while in area A2? What will happen to the substance if the pressure is increased while at point X1? What will happen to the substance if the temperature is increased while at point X1? What will happen to the substance if the temperature is decreased while at point X1? Explain the significance of point X2. 6. What is STP? Why is such a concept necessary when dealing with gases? 32 7. Describe the relationships between pressure, volume, temperature, and moles. 8. List the Empirical Gas Laws and the pneumatic chemist responsible for the law. 9. How is the Ideal Gas Law different from the other gas laws? Why is it useful? 10. What are the properties of an ideal gas? How do they differ from real gases? 11. Describe the Kinetic Molecular Theory and its relationship to Pressure, Volume, and Temperature. 12. Define and compare Diffusion and Effusion. 13. How is molecular speed related to molar mass? 33 Calculations: (x points) Show all of your work and circle your final answer to receive full credit! 14. Convert the following: From To A. 12.7 psi torr B. 3.75 atm bar C. 925.6 mmHg Pa D. 63.25 inHg atm Answer 15.) A sample of gas contains He at 0.15 atm, N2 at 1.35 atm, and CO2 at 0.25 atm. What is the total pressure of the sample in kilopascals (kPa)? 16.) A sample of gas at a total pressure of 1545.2 mmHg contains 15.72 g H2, 30.14 g O2, & 54.16 g N2. What is the partial pressure of each gas? 17.) What is the total weight of the atmosphere pushing in on a ball with a diameter of 2.50 inches? (S.A. = 4r2) 18). The cap of a soda bottle has a diameter of 1.125 inches. If the bottle is pressurized to 55.0 psi, what is the total force (in pounds) that is pushing out on the cap? (S.A. = r2) 19.) Complete the following table assuming STP: Gas Formula Mass (g) A. Xenon B. Nitrogen dioxide C. Nitrogen Xe Mw (g/mol) Moles Volume (L) 92.783 NO2 N2 0.387 6.394 20.) What volume will 16.873 g of oxygen occupy at STP? 21.) How many moles of argon are in 43.78 L at STP? Air Pressure  14.7 psi = 1 atm = 760 mmHg = 29.92 inHg = 760 torr = 1.01325 bar = 101,325 Pa = 101.325 kPa R = 0.08205746 atmL/molK = 8.314472 kPaL/molK = 62.36367 mmHgL/molK 34 22.) What is the mass of acetylene, C2H2, in 17.43 L at STP? 23.) 67.3 L of Xenon at 723.5 mmHg is compressed to 12.7 L. What is the new pressure? 24) A 12.25 mL sample of H2 at 15°C is heated to 85°C. What is the new volume? 25) 97.6 L of N2 at 850.0°C is cooled to produce a volume of 3.8 L. What is the new temperature? 26) A sample of gas at 3.25 atm & 25.0°C is heated to 750.6°C. What is the new pressure? 27) A gas is at 825.6 mmHg & 78°C. The pressure is decreased to 473.5 mmHg. What is the new Temperature? 28) 33.7 L of O2 at 2.7 atm & 15°C expands to 44.2 L while the pressure increases to 3.0 atm. What is the new temperature? 29) 19.9 L of Cl2 at 455.3 mmHg & 84.6°C is cooled to 25.3°C and the pressure decreases to 374.3 mmHg. What is the new volume of the gas? 30) 825.6 mL of a gas at -35.8°C is at 3.25 atm. If the volume is decreased to 500.0 mL and the temperature increased to 100.0°C, what is the new pressure? 31) What mass of F2 is in a 15.75 L container with a pressure of 383,920 Pa at 25.4°C? Air Pressure  14.7 psi = 1 atm = 760 mmHg = 29.92 inHg = 760 torr = 1.01325 bar = 101,325 Pa = 101.325 kPa R = 0.08205746 atmL/molK = 8.314472 kPaL/molK = 62.36367 mmHgL/molK 35 32) 243.49 grams of Argon (Ar) gas are in a 53.21 L container at -131.8°C. What is the pressure? 33) What volume will 15.0 g of methane (CH4) occupy at 0.488 bar and 457.3°C? 34) 0.0184 moles of PH3 has a pressure of 7503 mmHg and volume of 0.0471 L. What is the temperature of the gas? 35) What is the molar mass of an unknown gas if 0.220 g of the gas exerts a pressure of 125.7 torr in a 542.6 mL container at 20.7 °C? 36) A container with a volume of 755 cm3 holds 0.785 g carbon dioxide at 175.0 °C. What is the pressure of the gas? 37) What is the density of phosphorus trichloride at 35.75 inHg and 90.7 °C? 38) An unknown gas effuses 6.78 times slower than helium. a)What is the molar mass of the gas? b) What is the pressure of 4.75 g of the unknown gas in a 750.0 mL container at 24.7 °C? 39) Butane, C4H10, effuses through a barrier at a rate of 9.86x10-4 mol/hr while an unknown gas effuses at a rate of 7.63x10-4 mol/hr. What is the molar mass of the unknown gas? Air Pressure  14.7 psi = 1 atm = 760 mmHg = 29.92 inHg = 760 torr = 1.01325 bar = 101,325 Pa = 101.325 kPa R = 0.08205746 atmL/molK = 8.314472 kPaL/molK = 62.36367 mmHgL/molK 36 125 °C 40) ___ S8(s) + ___ F2(g)   ___ SF6(g) 25.5 bar (H = -9,672 kJ) a) What volume of product can be made from 9.76 L of fluorine at reaction conditions? b) What volume of fluorine, at reaction conditions, is required to produce 96.87 g of product? d) What amount of energy is released with the formation of 43.87 L of product at reaction conditions? 41) ___ Ca(s) + ___ H2O(l)  (H = -987 kJ) a)What volume of hydrogen will be produced from 19.63 g calcium at 23.8 °C and 15.87 psi? b) What mass of calcium is required to produce 187.3 mL of hydrogen at room temperature and 963.8 torr? c) What amount of energy is released with the production of 88.33 L of hydrogen at 110.8 kPa and 24.5 °C? 42) ___ Zn(s) + ___ H2SO4(aq)  a) 38.59 mL of gas is collected over water at 25.0 °C & 115 kPa. What mass of zinc reacted? b) 976.6 mL of gas is collected over water at 35.0 °C & 99,876 Pa. What mass of acid reacted? c) At what pressure will 87.6 L of gas be collected over water at 50.0 °C if 98.76 g zinc reacts with excess sulfuric acid? Air Pressure  14.7 psi = 1 atm = 760 mmHg = 29.92 inHg = 760 torr = 1.01325 bar = 101,325 Pa = 101.325 kPa R = 0.08205746 atmL/molK = 8.314472 kPaL/molK = 62.36367 mmHgL/molK 37