Question 1

Two moles of neon gas at 20.0°C are heated to 350°C while the volume is kept constant.The density of the gas

Accepted Answer

A) decreases. 
B) increases. 
C) remains the same. 
D) Not enough information was given to answer the question. 
A) decreases. 
B) increases. 
C) remains the same. 
D) Not enough information was given to answer the question.

Question 2

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 4.32 g of Al reacts with excess NaOH?

Accepted Answer

A) 2.39 L 
B) 3.59 L 
C) 5.38 L 
D) 5.88 L 
A) 2.39 L 
B) 3.59 L 
C) 5.38 L 
D) 5.88 L

Question 3

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?

Accepted Answer

A) diagram (2) 
B) diagram (3) 
C) diagram (4) 
A) diagram (2) 
B) diagram (3) 
C) diagram (4)

Question 4

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.

Accepted Answer

The answer of According to the kinetic molecular theory of...

Question 5

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?

Accepted Answer

A) drawing (b) 
B) drawing (c) 
C) drawing (d) 
A) drawing (b) 
B) drawing (c) 
C) drawing (d)

Question 6

A gas occupies 22.4 L at STP and 16.5 L at 100°C and 1.75 atm pressure.How many moles of gas did the system gain or lose?

Accepted Answer

A) 0.06 moles gained 
B) 0.03 moles gained 
C) 0.03 moles lost 
D) 0.06 moles lost 
A) 0.06 moles gained 
B) 0.03 moles gained 
C) 0.03 moles lost 
D) 0.06 moles lost

Question 7

Cyanogen is a gas which contains 46.2% C and 53.8% N by mass.At a temperature of 25°C and a pressure of 750 mm Hg,1.50 g of cyanogen occupies 0.714 L.What is the molecular formula of cyanogen?

Accepted Answer

A) CN 
B) C2N2 
C) C3N4 
D) C4N5 
A) CN 
B) C2N2 
C) C3N4 
D) C4N5

Question 8

At what temperature will sulfur hexafluoride molecules have the same average speed as argon atoms at 20°C?

Accepted Answer

A) -22.0°C 
B) 73.2°C 
C) 381°C 
D) 799°C 
A) -22.0°C 
B) 73.2°C 
C) 381°C 
D) 799°C

Question 9

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.  
-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?

Accepted Answer

A) 25 mm Hg 
B) 725 mm Hg 
C) 750 mm Hg 
D) 775 mm Hg 
A) 25 mm Hg 
B) 725 mm Hg 
C) 750 mm Hg 
D) 775 mm Hg

Question 10

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 752 torr and the level of mercury in the arm connected to the container is 9.60 cm higher than the level of mercury open to the atmosphere?

Accepted Answer

A) 656 mm Hg 
B) 742 mm Hg 
C) 762 mm Hg 
D) 848 mm Hg 
A) 656 mm Hg 
B) 742 mm Hg 
C) 762 mm Hg 
D) 848 mm Hg

Question 11

What is the Celsius temperature of 100.0 g of chlorine gas in a 4.00-L container at 800 mm Hg?

Accepted Answer

A) 309°C 
B) -236°C 
C) 236°C 
D) -309°C 
A) 309°C 
B) -236°C 
C) 236°C 
D) -309°C

Question 12

What is the temperature of N2 gas if the average speed (actually the root-mean-square speed)of the molecules is 750 m/s?

Accepted Answer

A) 0.842 K 
B) 6.31 × 102 K 
C) 3.16 × 102 K 
D) 0.421 K 
A) 0.842 K 
B) 6.31 × 102 K 
C) 3.16 × 102 K 
D) 0.421 K

Question 13

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)

Accepted Answer

Question 14

Which law does the equation,   = k represent?

Accepted Answer

A) Avogadro's law 
B) Boyle's law 
C) Charles' law 
D) Graham's law 
A) Avogadro's law 
B) Boyle's law 
C) Charles' law 
D) Graham's law

Question 15

In a flask containing 2.00 mol of Ar,3.00 mol of HCN,and 5.00 mol of N2 at STP the partial pressure of He is ________ mm Hg.

Accepted Answer

Question 16

A balloon contains 0.76 mol N2,0.18 mol Ar,0.031 mol He,and 0.026 mol H2 at 739 mm Hg.What is the partial pressure of Ar?

Accepted Answer

A) 19 mm Hg 
B) 23 mm Hg 
C) 130 mm Hg 
D) 560 mm Hg 
A) 19 mm Hg 
B) 23 mm Hg 
C) 130 mm Hg 
D) 560 mm Hg

Question 17

What is the total pressure in a 10.0 L flask which contains 0.200 mol of H2(g)and 0.215 mol of N2(g)at 20.0°C?

Accepted Answer

A) 0.306 atm 
B) 0.681 atm 
C) 0.693 atm 
D) 0.998 atm 
A) 0.306 atm 
B) 0.681 atm 
C) 0.693 atm 
D) 0.998 atm

Question 18

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

Accepted Answer

A) HCN 
B) O2 
C) Xe 
D) BF3 
A) HCN 
B) O2 
C) Xe 
D) BF3

Question 19

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

Accepted Answer

A) 2.27 m/s 
B) 7.57 m/s 
C) 71.7 m/s 
D) 239 m/s 
A) 2.27 m/s 
B) 7.57 m/s 
C) 71.7 m/s 
D) 239 m/s

Question 20

A carbon dioxide monitoring product provides a reading of 202 ppm.Calculate the percent carbon dioxide by volume.

Accepted Answer

A) 2.02 
B) 0.0202 
C) 0.202 
D) 20.2 
A) 2.02 
B) 0.0202 
C) 0.202 
D) 20.2

Exam 10: Gases: Their Properties and Behavior

Two moles of neon gas at 20.0°C are heated to 350°C while the volume is kept constant.The density of the gas

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 4.32 g of Al reacts with excess NaOH?

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.

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 gas occupies 22.4 L at STP and 16.5 L at 100°C and 1.75 atm pressure.How many moles of gas did the system gain or lose?

Cyanogen is a gas which contains 46.2% C and 53.8% N by mass.At a temperature of 25°C and a pressure of 750 mm Hg,1.50 g of cyanogen occupies 0.714 L.What is the molecular formula of cyanogen?

At what temperature will sulfur hexafluoride molecules have the same average speed as argon atoms at 20°C?

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 752 torr and the level of mercury in the arm connected to the container is 9.60 cm higher than the level of mercury open to the atmosphere?

What is the Celsius temperature of 100.0 g of chlorine gas in a 4.00-L container at 800 mm Hg?

What is the temperature of N2 gas if the average speed (actually the root-mean-square speed)of the molecules is 750 m/s?

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)

Which law does the equation, = k represent?

In a flask containing 2.00 mol of Ar,3.00 mol of HCN,and 5.00 mol of N2 at STP the partial pressure of He is ________ mm Hg.

A balloon contains 0.76 mol N2,0.18 mol Ar,0.031 mol He,and 0.026 mol H2 at 739 mm Hg.What is the partial pressure of Ar?

What is the total pressure in a 10.0 L flask which contains 0.200 mol of H2(g)and 0.215 mol of N2(g)at 20.0°C?

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

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

A carbon dioxide monitoring product provides a reading of 202 ppm.Calculate the percent carbon dioxide by volume.

Chemical Tools: Experimentation and Measurement

Atoms, molecules, and Ions

Mass Relationships in Chemical Reactions

Reactions in Aqueous Solutions

Periodicity and the Electronic Structure of Atoms

Ionic Compounds: Periodic Trends and Bonding

Covalent Bonding and Electron-Dot Structures

Covalent Compounds: Bonding Theories and Molecular Structure

Thermochemistry: Chemical Energy

Liquids, solids, and Phase Changes

Solutions and Their Properties

Chemical Kinetics

Chemical Equilibrium

Aqueous Equilibria: Acids and Bases

Applications of Aqueous Equilibria

Thermodynamics: Entropy, free Energy, and Equilibrium

Electrochemistry

Nuclear Chemistry

Transition Elements and Coordination Chemistry

Metals and Solid-State Materials

The Main-Group Elements

Connections to Organic and Biological Chemistry

Filters

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 4.32 g of Al reacts with excess NaOH?

What is the temperature of N₂ gas if the average speed (actually the root-mean-square speed)of the molecules is 750 m/s?

If 1.0 mol of N₂ and 3.0 mol of H₂in 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)

In a flask containing 2.00 mol of Ar,3.00 mol of HCN,and 5.00 mol of N₂ at STP the partial pressure of He is ________ mm Hg.

A balloon contains 0.76 mol N₂,0.18 mol Ar,0.031 mol He,and 0.026 mol H₂ at 739 mm Hg.What is the partial pressure of Ar?

What is the total pressure in a 10.0 L flask which contains 0.200 mol of H₂(g)and 0.215 mol of N₂(g)at 20.0°C?