Question McGraw-Hill Ryerson Limited

Transcription

1 Question 1 Which of the following cannot be explained by considering the empty space between the particles of a gas? A) Gases are more compressible than liquids. B) Gases have lower viscosities than liquids. C) After thorough stirring, all gas mixtures are solutions. D) The density of a substance in the gas state is lower than in the liquid state. E) All of these can be explained by considering the empty space between the particles of a gas. 4-1

2 Question 2 A long glass tube, sealed at one end, has an inner diameter of 10.0 mm. The tube is filled with water and inverted into a pail of water. If the atmospheric pressure is 755 mm Hg, how high (in mm H 2 O) is the column of water in the tube? d Hg = 13.5 g/ml; d water = 1.00 g/ml A) 1.02 x 10 4 B) C) 9.44 x 10 2 D) 755 E) 1.79 x

3 Question 3 During an experiment it was observed that the volume of the gas involved increased. Which of the following would be a possible explanation of how this could have happened? A) decrease sample mass keeping temperature and pressure constant B) increase the pressure keeping mass and temperature constant C) increase temperature keeping mass and pressure constant D) decrease sample size, increase pressure keeping mass constant E) decrease temperature and sample mass keeping pressure constant. 4-3

4 4-4 Question 4 A sample of sulfur hexafluoride gas occupies a volume of 5.10 L at 198 ºC. Assuming that the pressure and amount of gas remain constant, what temperature (in ºC) is needed to reduce the volume to 2.50 L? A) -176 B) 688 C) 231 D) -42 E) 97

5 4-5 Question 5 A sample of chlorine gas is confined in a 5.0 L container at bar and 27ºC. What amount of gas (mol) is present in the sample? A) 514 mol B) mol C) mol D) mol E) 42.2 mol

6 4-6 Question 6 What is the density of Freon-11 (CFCl 3 ) at 120ºC and 1.5 bar? A) 6.3 g/l B) 21 g/l C) 0.63 g/l D) g/l E) Cannot determine with the information provided.

7 Question 7 A sample of liquid hydrocarbon known to consist of molecules with five carbon atoms is vaporized in a L flask by immersion in a water bath at 101ºC and a barometric pressure of 1.02 bar; subsequently, the gas is condensed to g of liquid. What is the molecular formula of the hydrocarbon? A) C 5 H 5 B) C 5 H 7 C) C 5 H 9 D) C 5 H 12 E) C 5 H

8 4-8 Question 8 What mass of potassium chlorate decomposes to potassium chloride and 638 ml of O 2 at 128ºC and 1.00 bar? 2KClO 3 2KCl + 3O 2 A) g B) g C) 2.35 g D) 3.53 g E) 1.56 g

9 4-9 Question 9 What is the effusion rate for O 2 compared to Kr? A) B) C) D) E) 7.197

10 4-10 Question 10 What will happen to the volume of a gas if its pressure is decreased from 2 bar to 1 bar, while its temperature is decreased from 200ºC to 100ºC? A) increase B) decrease C) remain same

11 4-11 Question 11 If the atmospheric pressure is mmhg and the difference in height in the diagram to the right is 5.4 cm, what is the pressure of the gas in the flask? A) mmhg B) mmhg C) mmhg D) mmhg

12 4-12 Question 12 For a fixed amount of gas at constant pressure, what will happen to the volume of a gas if the temperature is decreased? A) The volume will decrease. B) The volume will increase. C) The volume will remain unchanged. D) There is insufficient information to determine.

13 4-13 Question 13 Hydrogen gas exerts a pressure of 466 mm Hg in a container. What is this pressure in bar? A) bar B) bar C) bar D) 1.63 bar E) 1.65 bar

14 4-14 Question 14 A sample of an ideal gas has its volume doubled while its temperature remains constant. If the original pressure was 100 bar, what is the new pressure? A) 10 bar B) 50 bar C) 100 bar D) 200 bar E) 1000 bar

15 4-15 Question 15 Arrange the following gases in order of increasing rate of effusion. C 2 H 6, Ar, HCl, PH 3 A) Ar < HCl < PH 3 < C 2 H 6 B) C 2 H 6 < PH 3 < HCl < Ar C) Ar < PH 3 < C 2 H 6 < HCl D) C 2 H 6 < HCl < PH 3 < Ar E) Ar < PH 3 < HCl < C 2 H 6

16 4-16 Question 16 Nitrogen will behave most like an ideal gas A) at high temperature and high pressure. B) at high temperature and low pressure. C) at low temperature and high pressure. D) at low temperature and low pressure. E) at intermediate (moderate) temperature and pressure.

17 4-17 Question 17 At constant temperature and amount (mol), how is the pressure of a gas affected when the volume of the gas is increased? A) The pressure will increase. B) The pressure will decrease. C) The pressure will remain the same. D) There is insufficient information to determine.

18 4-18 Question 18 If you fill a balloon with 2.50 moles of gas at 28 C and a pressure of 1.20 bar, what is the volume of the balloon? A) 4.79 L B) 22.4 L C) 52.1 L D) 56.0 L

19 4-19 Question 19 What is the molar mass of a gas which has a density of 6.65 g/l at 25 C and 1.00 bar? A) 81.7 g/mol B) 149 g/mol C) 165 g/mol D) 496 g/mol

20 4-20 Question 20 A mixture of N 2 and O 2 has a total pressure of 0.95 bar. What is the partial pressure (in bar) of N 2 if there are 0.56 mol N 2 and 0.32 mol O 2 in the mixture? A) 0.30 bar B) 0.35 bar C) 0.53 bar D) 0.60 bar

21 Answer Key Chapter 4 1. E 2. A 3. C 4. D 5. B 6. A 7. D 8. E 9. A 10. A 11. D 12. A 13. C 14. B 15. A 16. B 17. B 18. C 19. C 20. D 4-21