CHEM 113 CHAPTER 9 AND 10 PRACTICE QUESTIONS AND ANSWERS CORRECT SOLUTION LATEST UPDATE 2024

1. Which of these properties is/are characteristics(s) of gases? 2. If the amount of a gas is tripled and the volume of the container is also tripled the new pressure of the gas will: 3. You’re at the zoo and have a big red 3.200 L helium balloon. The barometric pressure is 790.0 mm Hg. Then you hear the roar of a lion. Startled, you accidently release the balloon. It flies away. By the time it reaches the clouds the atmospheric pressure is only 0.3000 atm. What is the new volume of the balloon? 4. A gas sample is held at constant pressure. The gas occupies 3.62 L of volume when the temperature is 21.6°C. Determine the temperature at which the volume of the gas is 3.45 L. 5. The temperature of a specific amount of gas in a sealed container changes from 20.0°C to 40.0°C. If the volume remains constant, the pressure will change from 755 mmHg to 6. If 2.10 mol of argon gas occupies a volume of 89.0 L, what volume will 2.45 mol of argon occupy under the same conditions of temperature and pressure? 7. A gas sample has a volume of 4.50 L when the temperature is 28 oC and the pressure is 1.00 atm. What will be the new volume of the gas when the temperature is changed to 0.0 oC and the pressure to 850 torr? 8. A gas evolved during the fermentation of alcohol had a volume of 19.4 L at 17 °C and 746 mmHg. How many moles of gas were collected? 9. The density of a gas is measured at 1.653 g/L at 746 mmHg and 25.0 °C. What is its molar mass? 10.How many liters will 20.0 g of Br2 occupy at STP? 11. Which gas sample does not occupy a volume of 22.4L? 12. Which of the following gases has a density of 0.716 g/L at STP? 13. The volume of HCl gas required to react with excess Mg metal to produce 6.82 L of hydrogen gas at 2.19 atm and 35°C is ________ L. 2 HCl (g) Mg (s)  MgCl2 (s) H2 (g) 14. Calculate the volume of H2(g) at 273 K and 2.00 atm that will be formed when 275 mL of 0.725 M HCl (g) solution reacts with excess Mg to give hydrogen gas and aqueous magnesium chloride. 2 HCl (g) Mg (s)  MgCl2 (s) H2 (g) 15. What is the total pressure in atmospheres in a 10.0 L vessel containing 2.50 x 10-3 mol of H2, 1.00 x 10-3 mol of He, and 3.00 x 10-4 mol of Ne at 35.0 oC? 16. A sample of natural gas contains 8.24 moles of methane, 0.421 moles of ethane, and 0.116 moles of propane. If the total pressure of the gases is 1.23 x 103 mm Hg, what is the partial pressure of ethane? (1 atm = 760 mm Hg) Save rounding for the end. 17. Assume two cylinders at 27 °C are connected by a closed valve system. The right hand cylinder contains 3.0 L of He at 0.60 atm and the left hand cylinder contains 6.8 L of He at 2.0 atm. What is the total pressure (in atm) when the valve is opened? 18. The kinetic molecular theory of gases predicts pressure to increase as the temperature of a gas increases because: I. the average kinetic energy of the gas molecules increases. II. gas molecules collide more frequently with the container walls. III. there are more molecules per unit volume after raising the temperature. IV. the elasticity of the molecules increases. V. there are less molecules per unit volume after raising the temperature. 19. In response to Boyle's law, the pressure of a gas increases as the volume __________ because ________. 20. _______ is the passage of gas through a small hole and ____ is the mixing of gas molecules. 21. The number of sigma and pi bonds in the molecule below are 22. The molecular structure of the IO3- ion is best described as: 23. Select the correctly identified bond angles indicated in the structure below. i ii iii a) 180° 90° 90° b) 90° 120° 90° c) 180° 109.5° 109.5° d) 180° 120° 109.5° e) 180° 90° 120° 24. Select the correct molecular geometry of the left-most and right-most carbon atom in the molecule below. Left-most carbon Right-most carbon a) trigonal planar linear b) tetrahedral trigonal pyramidal c) tetrahedral trigonal planar d) trigonal pyramidal linear e) tetrahedral tetrahedral 25. Indicate the type of hybrid orbitals used by the central atom in TeF4