Chapter 5 1 The volume of a gas is inversely proportional to the pressure

Chemistry: A Molecular Approach, 2e (Tro)

Chapter 5 Gases

Multiple Choice Questions

1) An instrument used to atmospheric pressure is called a

A) barometer

B) manometer

C) sphygmomanometer

D) spectrophotometer

E) spectrometer

2) An instrument used to measure the pressure of a gas in a laboratory is called a

A) barometer

B) manometer

C) sphygmomanometer

D) spectrophotometer

E) spectrometer

3) An instrument used to measure blood pressure is called a

A) barometer

B) manometer

C) sphygmomanometer

D) spectrophotometer

E) spectrometer

4) The volume of a gas is proportional to the temperature of a gas is known as

A) Avogadro’s Law

B) Ideal Gas Law

C) Charles’s Law

D) Boyle’s Law

E) Dalton’s Law

5) The volume of a gas is proportional to number of moles of a gas is known as

A) Avogadro’s Law

B) Ideal Gas Law

C) Charles’s Law

D) Boyle’s Law

E) Dalton’s Law

6) The volume of a gas is inversely proportional to the pressure of a gas is known as

A) Avogadro’s Law

B) Ideal Gas Law

C) Charles’s Law

D) Boyle’s Law

E) Dalton’s Law

7) A scuba diver experiences ________ as she descends into the ocean water.

A) decrease of 1 atm for each 20 m of depth

B) decrease of 1 atm for each 10 m of depth

C) increase of 1 atm for each 20 m of depth

D) increase of 1 atm for each 10 m of depth

E) no difference in pressure

8) What volume (in mL) will a sample of F2 gas occupy in a syringe at 5.5 atm, if the F2 has a volume

of 25.0 mL at 1.2 atm?

A) 11 mL

B) 17 mL

C) 3.8 mL

D) 5.5 mL

E) 7.6 mL

9) If a sample of 0.29 moles of Ar occupies 3.8 L under certain conditions, what volume will 0.66 moles

occupy under the same conditions?

A) 12 L

B) 8.6 L

C) 17 L

D) 5.0 L

E) 15 L

10) A syringe contains 0.65 moles of He gas that occupy 750.0 mL. What volume (in L) of gas will the

syringe hold if 0.35 moles of Ne is added?

A) 0.87 L

B) 4.9 L

C) 1.2 L

D) 2.1 L

E) 1.9 L

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11) To what temperature must a balloon, initially at 25°C and 2.00 L, be heated in order to have a

volume of 6.00 L?

A) 993 K

B) 403 K

C) 75 K

D) 655 K

E) 894 K

12) A large balloon is initially filled to a volume of 25.0 L at 353 K and a pressure of 2575 mm Hg.

What volume of gas will the balloon contain at 1.35 atm and 253 K?

A) 22.2 L

B) 87.5 L

C) 11.4 L

D) 45.0 L

E) 58.6 L

13) A syringe initially holds a sample of gas with a volume of 285 mL at 355 K and 1.88 atm. To what

temperature must the gas in the syringe be heated/cooled in order to have a volume of 435 mL at 2.50

atm?

A) 139 K

B) 572 K

C) 175 K

D) 466 K

E) 721 K

14) A sample of gas initially has a volume of 859 mL at 565 K and 2.20 atm. What pressure will the

sample have if the volume changes to 268 mL while the temperature is increased to 815 K?

A) 10.2 atm

B) 9.83 atm

C) 15.3 atm

D) 6.53 atm

E) 1.05 atm

15) What pressure will 14.0 g of CO exert in a 3.5 L container at 75°C?

A) 4.1 atm

B) 5.0 atm

C) 6.4 atm

D) 1.1 atm

E) 2.3 atm

16) What mass of NO2 is contained in a 13.0 L tank at 4.58 atm and 385 K?

A) 18.8 g

B) 53.1 g

C) 24.4 g

D) 86.7 g

E) 69.2 g

17) What is the volume of 5.60 g of O2 at 7.78 atm and 415K?

A) 1.53 L

B) 565 L

C) 24.5 L

D) 25.0 L

E) 0.766 L

18) Using the graph below, determine the gas that has the lowest density at STP.

A) A

B) B

C) C

D) D

E) All of the gases have the same density at STP.

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19) Using the graph below, determine the gas that has the highest density at STP.

A) A

B) B

C) C

D) D

E) All of the gases have the same density at STP.

20) Which of the following will cause the volume of an ideal gas to triple in value?

A) Raising the temperature from 25°C to 75°C at constant pressure.

B) Lowering the absolute temperature by a factor of 3 at constant pressure.

C) Raising the absolute temperature by a factor of 3 while increasing the pressure by a factor of 3.

D) Lowering the absolute temperature by a factor of 3 while increasing the pressure by a factor of 3.

E) Lowering the pressure by a factor of 3 while the temperature stays constant.

21) Determine the density of CO2 gas at STP.

A) 1.96 g/L

B) 1.80 g/L

C) 2.24 g/L

D) 4.46 g/L

E) 5.10 g/L

22) Determine the density of NH3 gas at 435 K and 1.00 atm.

A) 2.10 g/L

B) 0.477 g/L

C) 0.321 g/L

D) 2.24 g/L

E) 0.851 g/L

23) A 0.334 g sample of an unknown halogen occupies 109 mL at 398 K and 1.41 atm. What is the

identity of the halogen?

A) Br2

B) F2

C) Cl2

D) I2

E) Ge

24) A 0.465 g sample of an unknown compound occupies 245 mL at 298 K and 1.22 atm. What is the

molar mass of the unknown compound?

A) 26.3 g/mol

B) 33.9 g/mol

C) 12.2 g/mol

D) 38.0 g/mol

E) 81.8 g/mol

25) A compound is found to be 30.45% N and 69.55 % O by mass. If 1.63 g of this compound occupy

389 mL at 0.00°C and 775 mm Hg, what is the molecular formula of the compound?

A) NO2

B) N2O

C) N4O2

D) N2O5

E) N2O4

26) Define hypoxia.

A) oxygen starvation

B) increased oxygen concentration in body tissues

C) increased nitrogen concentration in body tissues and fluids

D) nitrogen starvation

27) Define vapor pressure.

A) partial pressure of water in a liquid mixture

B) partial pressure of water in a gaseous mixture

C) condensation of water

D) water dissolved in a liquid

E) water molecules

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28) The total pressure of a gas mixture is the sum of the partial pressure of its components is known as

A) Avogadro’s Law

B) Ideal Gas Law

C) Charles’s Law

D) Boyle’s Law

E) Dalton’s Law

29) A gas mixture consists of N2, O2, and Ne, where the mole fraction of N2 is 0.55 and the mole

fraction of Ne is 0.25. If the mixture is at STP in a 5.0 L container, how many molecules of O2 are

present?

A) 4.5 × 1022 molecules O2

B) 2.7 × 1022 molecules O2

C) 3.7 × 1023 molecules O2

D) 1.1 × 1023 molecules O2

E) 9.3 × 1024 molecules O2

30) A mixture of 10.0 g of Ne and 10.0 g Ar have a total pressure of 1.6 atm. What is the partial

pressure of Ne?

A) 1.1 atm

B) 0.80 atm

C) 0.54 atm

D) 0.40 atm

E) 1.3 atm

31) The following reaction is used to generate hydrogen gas in the laboratory. If 243 mL of gas is

collected at 25°C and has a total pressure of 745 mm Hg, what mass of hydrogen is produced? A

possibly useful table of water vapor pressures is provided below.

Mg(s) + 2 HCl(aq) → MgCl2(aq) + H2(g) T (°C) P (mm Hg)

20 17.55

25 23.78

30 31.86

A) 0.0196 g H2

B) 0.0717 g H2

C) 0.0190 g H2

D) 0.0144 g H2

E) 0.0449 g H2

32) A syringe contains 589 mL of CO at 325 K and 1.2 atm pressure. A second syringe contains 473

mL of N2 at 298 K and 2.6 atm. What is the final pressure if the contents of these two syringes are

injected into a 1.00 L container at STP?

A) 0.59 atm

B) 1.1 atm

C) 1.7 atm

D) 1.9 atm

E) 3.8 atm

33) What pressure would a gas mixture in a 10.0 L tank exert if it were composed of 48.5 g He and 94.6

g CO2 at 398 K?

A) 39.6 atm

B) 7.02 atm

C) 32.6 atm

D) 46.6 atm

E) 58.7 atm

34) Determine the volume of O2 (at STP) formed when 50.0 g of KClO3 decomposes according to the

following reaction. The molar mass for KClO3 is 122.55 g/mol.

2 KClO3(s) → 2 KCl(s) + 3 O2(g)

A) 9.14 L

B) 8.22 L

C) 12.3 L

D) 13.7 L

E) 14.6 L

35) Determine the volume of H2S (at 375 K and 1.20 atm) needed to produce 55.0 g of S. Assume that

there is excess SO2 present.

2 H2S(g) + SO2(g) → 3 S(s) + 2 H2O(g)

A) 44.0 L

B) 29.3 L

C) 22.7 L

D) 34.1 L

E) 66.0 L

36) How many molecules of XeF6 are formed from 12.9 L of F2 (at 298 K and 2.60 atm) according to

the following reaction? Assume that there is excess Xe.

Xe(g) + 3 F2(g) → XeF6(g)

A) 1.21 × 1023 molecules XeF6

B) 8.25 × 1023 molecules XeF6

C) 2.75 × 1023 molecules XeF6

D) 7.29 × 1023 molecules XeF6

E) 1.37 × 1023 molecules XeF6

37) Determine the theoretical yield and the percent yield if 21.8 g of K2CO3 is produced from reacting

27.9 g KO2 with 29.0 L of CO2 (at STP). The molar mass of KO2 = 71.10 g/mol and K2CO3 = 138.21

g/mol.

4 KO2(s) + 2 CO2(g) → 2 K2CO3(s) + 3 O2(g)

A) 27.1 g, 80.4 % yield

B) 179 g, 12.2 % yield

C) 91.7 g, 23.8 % yield

D) 206 g, 10.6 % yield

E) 61.0 g, 35.7 % yield

38) Determine the volume of SO2 (at STP) formed from the reaction of 96.7 g of FeS2 and 55.0 L of O2

(at 398 K and 1.20 atm). The molar mass of FeS2 is 119.99 g/mol.

4 FeS2(s) + 11 O2(g) → 2 Fe2O3(s) + 8 SO2(g)

A) 36.1 L

B) 45.3 L

C) 18.1 L

D) 27.6 L

E) 32.9 L

39) Determine the mass of water formed when 12.5 L NH3 (at 298 K and 1.50 atm) is reacted with 18.9

L of O2 (at 323 K and 1.1 atm).

4 NH3(g) + 5 O2(g) → 4 NO(g) + 6 H2O(g)

A) 17.0 g H2O

B) 20.7 g H2O

C) 37.7 g H2O

D) 13.8 g H2O

E) 27.9 g H2O

40) Determine the total volume of all gases (at STP) formed when 50.0 mL of TNT (C3H5(NO3)3, d =

1.60 g/mL, molar mass = 227.10 g/mol) reacts according to the following reaction.

4 C3H5(NO3)3(l) → 6 N2(g) + O2(g) + 12 CO2(g) + 10 H2O(g)

A) 4.93 L

B) 57.2 L

C) 29.6 L

D) 448 L

E) 175 L

41) A mixture of 1.0 mol He and 1.0 mol Ne are at STP in a rigid container. Which of the following

statements is TRUE?

A) Both gases have the same average kinetic energy.

B) Both gases contribute equally to the density of the mixture under these conditions.

C) Both gases have the same molecular speed.

D) The mixture has a volume of 22.4 L

E) All of the above are TRUE.

42) Which statement is TRUE about kinetic molecular theory?

A) A single particle does not move in a straight line.

B) The size of the particle is large compared to the volume.

C) The collisions of particles with one another is completely elastic.

D) The average kinetic energy of a particle is not proportional to the temperature.

43) Which of the gases in the graph below has the largest molar mass?

A) A

B) B

C) C

D) D

E) There is not enough information to determine.

44) Calculate the root mean square velocity of nitrogen molecules at 25°C.

A) 729 m/s

B) 515 m/s

C) 149 m/s

D) 297 m/s

45) The rate of effusion of two different gases is known as

A) Avogadro’s Law

B) Graham’s Law

C) Charles’s Law

D) Boyle’s Law

E) Dalton’s Law

46) Give the definition for diffusion.

A) gas molecules mix equally

B) gas molecules spread out in a concentration gradient

C) gas molecules escape from a container into a vacuum through a small hole

D) average distance between collisions

E) gas molecules mix unequally

47) The rate of effusion of oxygen to an unknown gas is 0.935. What is the other gas?

A) Ne

B) Ar

C) F2

D) N2

48) Which of the following statements is TRUE?

A) Particles of different masses have the same average speed at a given temperature.

B) The larger a molecule, the faster it will effuse.

C) At very high pressures, a gas will occupy a larger volume than predicted by the ideal gas law.

D) For a given gas, the lower the temperature, the faster it will effuse.

E) None of the above statements are true.

49) Which of the following statements is TRUE?

A) At a given temperature, lighter gas particles travel more slowly than heavier gas particles.

B) The smaller a gas particle, the slower it will effuse

C) The higher the temperature, the lower the average kinetic energy of the sample.

D) At low temperatures, intermolecular forces become important and the pressure of a gas will be lower

than predicted by the ideal gas law.

E) None of the above statements are true.

50) Which of the following compounds will behave LEAST like an ideal gas at low temperatures?

A) He

B) SO2

C) H2

D) N2

E) F2

51) This equation is used to calculate the properties of a gas under nonideal conditions.

A) Charles’s Law

B) Avogadro’s Law

C) Boyle’s Law

D) van der Waals equation

E) Dalton’s Law

Algorithmic Questions

1) Convert 1.50 atm to mm Hg.

A) 760 mm Hg

B) 875 mm Hg

C) 1140 mm Hg

D) 1000 mm Hg

E) 1520 mm Hg

2) Convert 1.50 atm to torr.

A) 760 torr

B) 875 torr

C) 1140 torr

D) 1000 torr

E) 1520 torr

3) Convert 1.75 atm to psi.

A) 52.4 psi

B) 875 psi

C) 25.7 psi

D) 1000 psi

E) 1330 psi

4) The atmospheric pressure is 700 mm Hg. What is the pressure in inches of Hg?

A) 16.0 in Hg

B) 0.921 in Hg

C) 13.5 in Hg

D) 27.6 in Hg

E) 32.5 in Hg

5) The atmospheric pressure is 715 mm Hg. What is the pressure in torr?

A) 715 torr

B) 28.1 torr

C) 13.8 torr

D) 31.8 torr

E) 760 torr

6) What is the pressure in a gas container that is connected to an open-end U-tube manometer if the

pressure of the atmosphere is 742 torr and the level of mercury in the arm connected to the container is

8.60 cm higher than the level of mercury open to the atmosphere?

A) 656 mm Hg

B) 733 mm Hg

C) 751 mm Hg

D) 828 mm Hg

7) If the pressure in a gas container that is connected to an open-end U-tube manometer is 116 kPa and

the pressure of the atmosphere at the open end of the tube is 752 mm Hg, the level of mercury in the

tube will

A) be 118 mm higher in the arm open to the atmosphere.

B) be 118 mm higher in the arm connected to the gas cylinder.

C) be 870 mm higher in the arm open to the atmosphere.

D) be 870 mm higher in the arm connected to the gas cylinder.

8) A container filled with gas is connected to an open-end manometer that is filled with mineral oil. The

pressure in the gas container is 753 mm Hg and atmospheric pressure is 724 mm. How high will the

level rise in the manometer if the densities of Hg and mineral oil are 13.6 g/mL and 0.822 g/mL

respectively?

A) 1.75 mm

B) 23.8 mm

C) 29.0 mm

D) 480 mm

9) What volume will a balloon occupy at 1.0 atm, if the balloon has a volume of 8.8 L at 4.4 atm?

A) 2.0 L

B) 0.50 L

C) 39 L

D) 13 L

E) 4.4 L

10) A gas occupies 4.23 L at 2.25 atm. What is the volume at 3.46 atm?

A) 6.50 L

B) 1.84 L

C) 2.75 L

D) 32.9 L

E) 0.364 L

11) A sample of 0.200 moles of nitrogen occupies 0.400 L. Under the same conditions, what number of

moles occupies 1.200 L?

A) 0.600 moles

B) 0.0667 moles

C) 2.40 moles

D) 0.0960 moles

12) To what volume will a sample of gas expand if it is heated from 50.0∘C and 2.33 L to 500.0°C?

A) 5.58 L

B) 23.3 L

C) 0.233 L

D) 0.97 L

E) 0.184 L

13) A gas is at 35.0°C and 3.50 L. What is the temperature at 7.00 L?

A) 343°C

B) 70.0°C

C) 616°C

D) 1.16°C

E) 17.5°C

14) A fixed amount of gas at 25.0°C occupies a volume of 10.0 L when the pressure is 667 torr. Use

Boyle’s law to calculate the pressure (torr) when the volume is reduced to 7.88 L at a constant

temperature of 25.0°C.

A) 846 torr

B) 0.118 torr

C) 5.26 × torr

D) 526 torr

E) 1.11 torr

15) The volume of 350. mL of gas at 25°C is decreased to 135 mL at constant pressure. What is the final

temperature of the gas?

A) -158°C

B) 9.6°C

C) 65°C

D) 500°C

16) A fixed amount of gas at 25.0°C occupies a volume of 10.0 L when the pressure is 629 torr. Use

Charles’s law to calculate the volume (L) the gas will occupy when the temperature is increased to

121°C while maintaining the pressure at 629 torr.

A) 10.9 L

B) 13.2 L

C) 2.07 L

D) 7.56 L

E) 48.4 L

17) A basketball is inflated to a pressure of 1.90 atm in a 24.0°C garage. What is the pressure of the

basketball outside where the temperature is -1.00°C?

A) 1.74 atm

B) 1.80 atm

C) 2.00 atm

D) 2.08 atm

18) A balloon filled with helium gas at 20°C occupies 4.91 L at 1.00 atm. The balloon is immersed in

liquid nitrogen at -196°C, while the pressure is raised to 5.20 atm. What is the volume of the balloon in

the liquid nitrogen?

A) 0.25 L

B) 3.6 L

C) 6.7 L

D) 97 L

19) What pressure (in atm) will 0.44 moles of CO2 exert in a 2.6 L container at 25°C?

A) 0.35 atm

B) 4.1 atm

C) 4.7 atm

D) 8.6 atm

E) 3.6 atm

20) How many moles of Ar are contained in a 5.00 L tank at 155°C and 2.80 atm?

A) 0.399 moles

B) 1.10 moles

C) 2.51 moles

D) 0.455 moles

E) 0.289 moles

21) Calculate the temperature, in K, of 2.20 moles of gas occupying 3.30 L at 3.50 atm.

A) 64.0 K

B) -209 K

C) 337 K

D) 28.0 K

22) What pressure will 2.6 x 1023 molecules of N2 exert in a 3.9 L container at 45°C?

A) 5.7 atm

B) 1.7 atm

C) 2.9 atm

D) 3.4 atm

E) 4.6 atm

23) How many molecules of He are contained in a 10.0 L tank at 7.53 atm and 485 K?

A) 1.89 × 1024 molecules

B) 1.14 × 1024 molecules

C) 8.32 × 1024 molecules

D) 4.89 × 1024 molecules

E) 3.63 × 1024 molecules

24) What is the volume of 9.783 x 1023 atoms of Kr at 9.25 atm and 512K?

A) 7.38 L

B) 3.69 L

C) 1.85 L

D) 15.4 L

E) 30.8 L

25) How many molecules of N2 are in a 400.0 mL container at 780 mm Hg and 135°C?

A) 7.01 × 1021 molecules

B) 7.38 × 1021 molecules

C) 2.12 × 1022 molecules

D) 2.23 × 1022 molecules

26) A 55.0-L steel tank at 20.0°C contains acetylene gas, C2H2, at a pressure of 1.39 atm. Assuming

ideal behavior, how many grams of acetylene are in the tank?

A) 3.17 g

B) 8.20 g

C) 82.9 g

D) 1210 g

27) What is the volume of 30.0 g of argon gas at 157°C and 2.50 kPa pressure?

A) 3.87 L

B) 10.6 L

C) 393 L

D) 1070 L

28) What is the Celsius temperature of 100.0 g of chlorine gas in a 55.0-L container at 800 mm Hg?

A) -23°C

B) 228°C

C) 250°C

D) 500°C

29) A gas bottle contains 0.250 mol of gas at 730 mm Hg pressure. If the final pressure is 1.15 atm, how

many moles of gas were added to the bottle?

A) 0.0262 mol

B) 0.0493 mol

C) 0.276 mol

D) 0.299 mol

30) A 2.75-L container filled with CO2 gas at 25°C and 225 kPa pressure springs a leak. When the

container is re-sealed, the pressure is 185 kPA and the temperature is 10°C. How many moles of gas

were lost?

A) 0.0335 mol

B) 0.728 mol

C) 0.882 mol

D) 3.39 mol

31) How many grams of F2 gas are there in a 5.00-L cylinder at 4.00 × 103 mm Hg and 23°C?

A) 19.5 g

B) 41.1 g

C) 500 g

D) 2.96 × 104 g

32) A 4.00-L flask contains nitrogen gas at 25°C and 1.00 atm pressure. What is the final pressure in the

flask if an additional 2.00 g of N2 gas is added to the flask and the flask cooled to -55°C?

A) 0.319 atm

B) 1.05 atm

C) 1.44 atm

D) 1.96 atm

33) Three identical flasks contain three different gases at standard temperature and pressure. Flask A

contains C2H4, flask B contains O3, and flask C contains F2. Which flask contains the largest number

of molecules?

A) flask A

B) flask B

C) flask C

D) All contain same number of molecules.

34) The density of nitric oxide (NO) gas at 1.21 atm and 54.1°C is ________ g/L.

A) 0.0451

B) 0.740

C) 1.35

D) 0.273

E) 8.2

35) The density of krypton gas at 1.21 atm and 50.0°C is ________ g/L.

A) 0.0456

B) 0.262

C) 0.295

D) 3.82

E) 7.65