Chapter 9 2 of the gas inside the above apparatus if the outside pressure

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98) What is the pressure (in mm Hg) of the gas inside the above apparatus if the outside pressure, Patm,

is 740 mm Hg and the difference in mercury levels, Δh, is 30 mm Hg?

A) 30 mm Hg

B) 710 mm Hg

C) 740 mm Hg

D) 770 mm Hg

99) What is the pressure (in mm Hg) of the gas inside the above apparatus if the outside pressure, Patm,

is 750 mm Hg and the difference in mercury levels, Δh, is 50 mm Hg?

A) 50 mm Hg

B) 700 mm Hg

C) 750 mm Hg

D) 800 mm Hg

100) What is the pressure (in mm Hg) of the gas inside the above apparatus if the outside pressure,

Patm, is 736 mm Hg and the difference in mercury levels, Δh, is 18 mm Hg?

A) 18 mm Hg

B) 718 mm Hg

C) 736 mm Hg

D) 754 mm Hg

101) What is the pressure (in mm Hg) of the gas inside the above apparatus if the outside pressure,

Patm, is 745 mm Hg and the difference in mercury levels, Δh, is 25 mm Hg?

A) 25 mm Hg

B) 720 mm Hg

C) 745 mm Hg

D) 770 mm Hg

The apparatus shown is called a closed-end manometer because the arm not connected to the gas sample

is closed to the atmosphere and is under vacuum.

102) What is the pressure (in mm Hg) of the gas inside the above apparatus if the outside pressure,

Patm, is 745 mm Hg and the difference in mercury levels, Δh, is 25 mm Hg?

A) 25 mm Hg

B) 720 mm Hg

C) 745 mm Hg

D) 770 mm Hg

103) What is the pressure (in mm Hg) of the gas inside the above apparatus if the outside pressure,

Patm, is 750 mm Hg and the difference in mercury levels, Δh, is 25 mm Hg?

A) 25 mm Hg

B) 725 mm Hg

C) 750 mm Hg

D) 775 mm Hg

104) When stopcock A of the open-end manometer shown below is opened, which drawing best

represents the result?

A) drawing (1)

B) drawing (2)

C) drawing (3)

D) drawing (4)

A glass tube has one end in a dish of mercury and the other end closed by a stopcock. The distance from

the surface of the mercury to the bottom of the stopcock is 800 mm, as indicated by the meter stick

shown in the drawing below. The apparatus is at 20°C, and the mercury level in the tube is the same as

that in the dish.

105) Which drawing best shows the approximate level of the mercury in the tube when the temperature

of the entire apparatus is lowered from +20°C to -20°C?

A) drawing (1)

B) drawing (2)

C) drawing (3)

D) drawing (4)

106) Which drawing best shows the approximate level of the mercury in the tube when a vacuum pump

is connected to the top of the tube, the stopcock opened, the tube is evacuated, the stopcock is closed,

and the pump is removed?

A) drawing (1)

B) drawing (2)

C) drawing (3)

D) drawing (4)

107) Which drawing best shows the approximate level of the mercury in the tube when a vacuum pump

is connected to the top of the tube, the stopcock opened, the tube is evacuated, the stopcock is closed,

and the pump is removed, and the stopcock is reopened?

A) drawing (1)

B) drawing (2)

C) drawing (3)

D) drawing (4)

108) Assume that you have a sample of gas in a cylinder with a moveable piston, as shown in diagram

(1). The initial pressure, number of moles, and temperature of the gas are noted on the diagram. Which

diagram (2)-(4) most closely represents the result of doubling the number of moles of gas while keeping

the pressure and temperature constant?

A) diagram (2)

B) diagram (3)

C) diagram (4)

109) Assume that you have a sample of gas in a cylinder with a moveable piston, as shown in diagram

(1). The initial pressure, number of moles, and temperature of the gas are noted on the diagram. Which

diagram (2)-(4) most closely represents the result of doubling the temperature while keeping the

pressure and number of moles of gas constant?

A) diagram (2)

B) diagram (3)

C) diagram (4)

Assume that you have a sample of gas in a cylinder with a moveable piston, as shown in diagram (1).

The initial pressure, number of moles, and temperature of the gas are noted on the diagram.

110) Which diagram (2)-(4) most closely represents the result of doubling the pressure while keeping

the temperature and number of moles of gas constant?

A) diagram (2)

B) diagram (3)

C) diagram (4)

111) Which diagram (2)-(4) most closely represents the result of doubling the pressure and doubling the

temperature while keeping the number of moles of gas constant?

A) diagram (2)

B) diagram (3)

C) diagram (4)

112) Assume that you have a sample of gas in a cylinder with a moveable piston, as shown in diagram

(1). The initial pressure, number of moles, and temperature of the gas are noted on the diagram. Which

diagram (2)-(4) most closely represents the result of doubling the pressure and number of moles of gas

while keeping the temperature constant?

A) diagram (2)

B) diagram (3)

C) diagram (4)

In the diagram below, nitrogen molecules are represented by unshaded spheres, oxygen molecules by

gray spheres, and chlorine molecules by black spheres.

113) If the total pressure in the container is 900 mm Hg, what is the partial pressure of nitrogen?

A) 90 mm Hg

B) 180 mm Hg

C) 270 mm Hg

D) 450 mm Hg

114) If the total pressure in the container is 900 mm Hg, what is the partial pressure of oxygen?

A) 90 mm Hg

B) 180 mm Hg

C) 270 mm Hg

D) 450 mm Hg

115) If the total pressure in the container is 900 mm Hg, what is the partial pressure of chlorine?

A) 90 mm Hg

B) 180 mm Hg

C) 270 mm Hg

D) 450 mm Hg

In the diagram below, helium atoms are represented by unshaded spheres, neon atoms by gray spheres,

and argon atoms by black spheres.

116) If the total pressure in the container is 900 mm Hg, what is the partial pressure of helium?

A) 90 mm Hg

B) 180 mm Hg

C) 270 mm Hg

D) 450 mm Hg

117) If the total pressure in the container is 900 mm Hg, what is the partial pressure of neon?

A) 90 mm Hg

B) 180 mm Hg

C) 270 mm Hg

D) 450 mm Hg

118) If the total pressure in the container is 900 mm Hg, what is the partial pressure of argon?

A) 90 mm Hg

B) 180 mm Hg

C) 270 mm Hg

D) 450 mm Hg

119) Assume that you have a mixture of nitrogen (molecular mass = 28 amu), represented by unshaded

spheres, and chlorine (molecular mass = 71 amu), represented by shaded spheres at 300 K. Which of the

drawings best represents the mixture?

A) drawing (a)

B) drawing (b)

C) drawing (c)

120) Three bulbs, two of which contain different gases and one of which is empty, are connected as

shown in drawing (a). Which drawing (b) – (d) best represents the system after the stopcocks are opened

and the system is allowed to come to equilibrium?

A) drawing (b)

B) drawing (c)

C) drawing (d)

121) Effusion of a 1:1 mixture of two gases, represented by unshaded and shaded spheres in the diagram

below, through a small pinhole produces the result shown below. The shaded spheres have a molecular

mass of 32 amu. Which gas molecules have the higher average speed and what is the molecular mass of

the unshaded molecules?

A) Unshaded molecules have higher average speed and molecular mass = 14 amu

B) Unshaded molecules have higher average speed and molecular mass = 21 amu

C) Unshaded molecules have lower average speed and molecular mass = 48 amu

D) Unshaded molecules have lower average speed and molecular mass = 72 amu

122) Effusion of a 1:1 mixture of two gases, represented by unshaded and shaded spheres in the diagram

below, through a small pinhole produces the result shown below. The shaded spheres have a molecular

mass of 20 amu. Which gas molecules have the higher average speed and what is the molecular mass of

the unshaded molecules?

A) Unshaded molecules have higher average speed and molecular mass = 14 amu

B) Unshaded molecules have higher average speed and molecular mass = 17 amu

C) Unshaded molecules have lower average speed and molecular mass = 24 amu

D) Unshaded molecules have lower average speed and molecular mass = 29 amu

9.2 Algorithmic Questions

1) 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

2) 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.

3) 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

4) 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

5) 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) 0.0 262 mol

B) 0. 0493 mol

C) 0. 276 mol

D) 0. 299 mol

6) 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

7) 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, raising the pressure 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

8) 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.

9) 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

10) 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) 0.0 335 mol

B) 0. 728 mol

C) 0. 882 mol

D) 3.39 mol

11) A 45.0-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) 2.60 g

B) 10.0 g

C) 67.8 g

D) 990 g

12) 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

13) A steel bottle contains argon gas at STP. What is the final pressure if the temperature is changed to

145°C?

A) 0. 653 atm

B) 0. 713 atm

C) 1. 40 atm

D) 1. 53 atm

14) A gas occupies 22.4 L at STP and 19.0 L at 100°C and 1.50 atm pressure. How many moles of gas

did the system gain or lose?

A) 0.08 moles gained

B) 0.01 moles gained

C) 0.01 moles lost

D) 0.0 7 moles lost

15) How many grams of NO gas are there in a 5.00-L cylinder at 4.00 × 103 mm Hg and 23°C?

A) 13.9 g

B) 32.1 g

C) 417 g

D) 2.47 × 104 g

16) 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

17) 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

18) A 0. 286-g sample of gas occupies 125 mL at 60. cm of Hg and 25°C. What is the molar mass of the

gas?

A) 5.9 g/mol

B) 44 g/mol

C) 59 g/mol

D) 71 g/mol

19) What is the density of hydrogen gas at STP?

A) 11.1 g/L

B) 0.0450 g/L

C) 0.0823 g/L

D) 0.0899 g/L

20) Which of the following would have a density of 1.37 g/L at 7.0°C and 0.987 atm?

A) N2

B) O2

C) Kr

D) Rn

21) Given three cylinders containing O2 gas at the same volume and pressure. Cylinder A is at – 20°C,

cylinder B is at – 15°F, cylinder C is at 260 K. Which cylinder contains the largest mass of oxygen?

A) cylinder A

B) cylinder B

C) cylinder C

D) All cylinders contain the same mass of O2.

22) The action of some commercial drain cleaners is based on the following reaction:

2 NaOH(s) + 2 Al(s) + 6 H2O(l) → 2 NaAl(OH)4(s) + 3 H2(g)

What is the volume of H2 gas formed at STP when 6.32 g of Al reacts with excess NaOH?

A) 3.50 L

B) 5.25 L

C) 7.87 L

D) 8.59 L

23) How many liters of oxygen are needed to exactly react with 19.8 g of methane at STP?

CH4(g) + 2 O2(g) → CO2(g) + 2 H2O(l)

A) 13.9 L

B) 27.8 L

C) 55.5 L

D) 60.5 L

24) When 14.0 g of zinc metal reacts with excess HCl, how many liters of H2 gas are produced at STP?

A) 0.2 08 L

B) 0. 416 L

C) 4.80 L

D) 9.60 L

25) How many grams of XeF6 are required to react with 0.579 L of hydrogen gas at 6.46 atm and 45°C

in the reaction shown below?

XeF6(s) + 3 H2(g) → Xe(g) + 6 HF(g)

A) 9.58 g

B) 11.7 g

C) 35.2 g

D) 106 g

26) A balloon contains 0.76 mol N2, 0.18 mol O2, 0.031 mol He and 0.026 mol H2 at 749 mm Hg.

What is the partial pressure of O2?

A) 20 mm Hg

B) 23 mm Hg

C) 140 mm Hg

D) 570 mm Hg

27) What is the total pressure in a 6.00-L flask which contains 0.127 mol of H2(g) and 0.288 mol of

N2(g) at 20.0°C?

A) 0. 510 atm

B) 0.681 atm

C) 1.16 atm

D) 1.66 atm

28) A 1.000 kg sample of nitroglycerine, C3H5N3O9, explodes and releases gases with a temperature of

1985°C at 1. 100 atm. What is the volume of gas produced?

4 C3H5N3O9(s) → 12 CO2(g) + 10 H2O(g) + 6 N2(g) + O2(g)

A) 742.2 L

B) 3525 L

C) 4730 L

D) 5378 L

29) In the laboratory, hydrogen gas is usually made by the following reaction:

Zn(s) + 2 HCl(aq) → H2(g) + ZnCl2(aq)

How many liters of H2 gas, collected over water at an atmospheric pressure of 752 mm Hg and a

temperature of 21.0°C, can be made from 3.566 g of Zn and excess HCl? The partial pressure of water

vapor is 18.65 mm Hg at 21.0°C.

A) 0. 0975 L

B) 1.30 L

C) 1.33 L

D) 1.36 L

30) A 0. 600 g sample containing Ag2O and inert material is heated, causing the silver oxide to

decompose according to the following equation:

2 Ag2O(s) → 4 Ag(s) + O2(g)

If 13.8 mL of gas are collected over water at 27°C and 1.00 atm external pressure, what is the percentage

of silver oxide in the sample? The partial pressure of water is 26.7 mm Hg at 27°C.

A) 10.4%

B) 20.9%

C) 41.8%

D) 44.8%

31) What is the average speed (actually the root-mean-square speed) of a neon atom at 27°C?

A) 5.78 m/s

B) 19.3 m/s

C) 183 m/s

D) 609 m/s

32) Which of the following gases has the highest average speed at 400K?

A) N2

B) O2

C) F2

D) Cl2

33) Which of the following gases has the lowest average speed at 25°C?

A) C3H8

B) Kr

C) CH3NH2

D) SO2

34) What is the temperature of NO2 gas if the average speed (actually the root-mean-square speed) of

the molecules is 750 m/s?

A) 1.38 K

B) 1.04 × 103 K

C) 1.38 × 103 K

D) 1.04 × 106 K

35) If NO and NH3 are allowed to effuse through a porous membrane under identical conditions, the

rate of effusion for NH3 will be ________ times that of NO .

A) 0.57

B) 0.75

C) 1.3

D) 1.8

9.3 Short Answer Questions

1) Under the same pressure and temperature conditions, the level of water inside a barometer will be

________ than the level of mercury inside the barometer by a factor equal to the ratio of the density of

________ over the density of ________.

2) At an atmospheric pressure of 745 mm Hg, what is the pressure of He gas inside a cylinder that is

attached to an open-end manometer in which the level of mercury in the open side of the manometer is

25 mm Hg higher than the side that is attached to the gas cylinder?

3) The pressure in a container of gas connected to an open-end mercury manometer in which the

mercury level is 22 cm lower in the side open to the atmosphere and the atmospheric pressure is

734 mm Hg is ________ mm Hg.

4) One mole of gas at 25°C in a 1.0-L flask has a ________ pressure than one mole of gas at 25°C in a

5.0-L flask.

5) One mole of gas at 25°C has a ________ volume than one mole of gas at standard temperature.

6) At STP if 1.00 mole of gas occupies 22.4 L then 0.200 mole of gas would occupy ________ L under

the same conditions.

7) When using the ideal gas law the temperature must be expressed in ________.

8) If one mole of gas occupies 22.4 L at STP the same gas would occupy ________ than 22.4 L at 25°C

and 738 mm Hg.

9) To two significant figures, by what factor will the pressure of an ideal gas change if the temperature

of the gas is changed from 100°C to 200°C?

10) If 0.40 mol of NaN3 reacts completely in the reaction shown below, then ________ L of N2 will be

produced at STP.

2 NaN3(s) → 2 Na(s) + 3 N2(g)

11) If 1.0 mol of N2 and 3.0 mol of H2 in a closed container initially at STP react completely in the

reaction shown below, then the final pressure in the flask will be ________ atm at 273 K.

N2(g) + 3 H2(g) → 2 NH3(g)

12) At STP the number of liters of O2 required to react with 11.2 liters of CH4 to form only CO2 and

H2O is ________ liters.

13) In a flask containing 2.00 mol of He, 3.00 mol of Ne, and 5.00 mol of Ar at STP the partial pressure

of He is ________ mm Hg.

14) If 1.0 gram each of Cl2, CO2, N2, and O2 are contained in a 5-L flask, the gas with the highest

partial pressure is ________.

15) According to the kinetic molecular theory of gases, the volume of the gas particles (atoms or

molecules) is ________ compared to the volume of the container in which the gas particles are held.

16) According to the kinetic molecular theory of gases, at 298 K the average kinetic energy of O2 is

________ the average kinetic energy of CO2.

17) According to the kinetic molecular theory of gases, what is the force of attraction of one N2

molecule for another N2 molecule?

18) According to the kinetic molecular theory of gases, raising the temperature of a gases increases the

average kinetic energy and the frequency of ________.

19) At 298 K which is larger rate of effusion or rate of diffusion?

20) According to Graham’s law, the rate of effusion of a gas is inversely proportional to the ________.

21) Gases do not behave ideally under conditions of ________ pressure and ________ temperature.

22) The region of the atmosphere that is closest to the earth’s surface is the ________.

23) The burning of sulfur-containing coal can lead to acid rain due to the formation of ________ acid.

24) The molecule believed to be most responsible for global warming is ________.

25) In the upper atmosphere, photochemical reactions involving organic molecules containing the

elements ________ and ________ generate products that lead to ozone depletion.