Question 1

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

Accepted Answer

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 
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

Question 2

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?

Accepted Answer

A)  0.0 262 mol 
B)  0. 0493 mol 
C)  0. 276 mol 
D)  0. 299 mol 
A)  0.0 262 mol 
B)  0. 0493 mol 
C)  0. 276 mol 
D)  0. 299 mol

Question 3

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?

Accepted Answer

A)  3.50 L 
B)  5.25 L 
C)  7.87 L 
D)  8.59 L 
A)  3.50 L 
B)  5.25 L 
C)  7.87 L 
D)  8.59 L

Question 4

The concentration of carbon monoxide in a sample of air is 9.2 ppm.There are ________ molecules of CO in 1.00 L of this air at 755 torr and 23°C.

Accepted Answer

A)  3.8 ×   
B)  2.2 ×   
C)  2.9 ×   
D)  1.7 ×   
E)  2.3 ×   
A)  3.8 ×   
B)  2.2 ×   
C)  2.9 ×   
D)  1.7 ×   
E)  2.3 ×

Question 5

Calculate the ratio of effusion rates of Cl2 to O2.

Accepted Answer

A)  47.7 
B)  0.451 
C)  2.22 
D)  1.49 
E)  0.671 
A)  47.7 
B)  0.451 
C)  2.22 
D)  1.49 
E)  0.671

Question 6

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?

Accepted Answer

A)  NO2 
B)  N2O 
C)  N4O2 
D)  N2O5 
E)  N2O4 
A)  NO2 
B)  N2O 
C)  N4O2 
D)  N2O5 
E)  N2O4

Question 7

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?

Accepted Answer

A)  39.6 atm 
B)  7.02 atm 
C)  32.6 atm 
D)  46.6 atm 
E)  58.7 atm 
A)  39.6 atm 
B)  7.02 atm 
C)  32.6 atm 
D)  46.6 atm 
E)  58.7 atm

Question 8

Which of the following gas samples would be most likely to behave ideally under the stated conditions?

Accepted Answer

A)  Ar at STP 
B)  CO at 200 atm and 25°C 
C)  SO2 at 2 atm and 0 K 
D)  N2 at 1 atm and -70°C 
E)  H2 at 400 atm and 25°C 
A)  Ar at STP 
B)  CO at 200 atm and 25°C 
C)  SO2 at 2 atm and 0 K 
D)  N2 at 1 atm and -70°C 
E)  H2 at 400 atm and 25°C

Question 9

Given the equation C2H6(g)+ O2(g)→ CO2(g)+ H2O(g)(not balanced),determine the number of liters of O2 consumed at STP when 270.0 grams of C2H6 is burned.

Accepted Answer

Question 10

An instrument used to measure atmospheric pressure is called a

Accepted Answer

A)  barometer. 
B)  manometer. 
C)  sphygmomanometer. 
D)  spectrophotometer. 
E)  spectrometer. 
A)  barometer. 
B)  manometer. 
C)  sphygmomanometer. 
D)  spectrophotometer. 
E)  spectrometer.

Question 11

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?

Accepted Answer

A)  0.0 335 mol 
B)  0. 728 mol 
C)  0. 882 mol 
D)  3.39 mol 
A)  0.0 335 mol 
B)  0. 728 mol 
C)  0. 882 mol 
D)  3.39 mol

Question 12

A 1.44-g sample of an unknown pure gas occupies a volume of 0.335 L at a pressure of   and a temperature of 100.0°C.The unknown gas is

Accepted Answer

A)  argon 
B)  helium 
C)  krypton 
D)  neon 
E)  xenon 
A)  argon 
B)  helium 
C)  krypton 
D)  neon 
E)  xenon

Question 13

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.

Accepted Answer

A)  0. 0975 L 
B)  1.30 L 
C)  1.33 L 
D)  1.36 L 
A)  0. 0975 L 
B)  1.30 L 
C)  1.33 L 
D)  1.36 L

Question 14

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

Accepted Answer

A)  Avogadro's Law. 
B)  Ideal Gas Law. 
C)  Charles's Law. 
D)  Boyle's Law. 
E)  Dalton's Law. 
A)  Avogadro's Law. 
B)  Ideal Gas Law. 
C)  Charles's Law. 
D)  Boyle's Law. 
E)  Dalton's Law.

Question 15

Given three cylinders containing O2 gas at the same volume and pressure.Cylinder A is at -15°C,cylinder B is at -5°F,cylinder C is at 255 K.Which cylinder contains the largest mass of oxygen?

Accepted Answer

A)  cylinder A 
B)  cylinder B 
C)  cylinder C 
D)  All cylinders contain the same mass of O2. 
A)  cylinder A 
B)  cylinder B 
C)  cylinder C 
D)  All cylinders contain the same mass of O2.

Question 16

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?

Accepted Answer

A)  139 K 
B)  572 K 
C)  175 K 
D)  466 K 
E)  721 K 
A)  139 K 
B)  572 K 
C)  175 K 
D)  466 K 
E)  721 K

Question 17

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

Accepted Answer

A)  A 
B)  B 
C)  C 
D)  D 
E)  There is not enough information to determine. 
A)  A 
B)  B 
C)  C 
D)  D 
E)  There is not enough information to determine.

Question 18

How many grams of KCl(s)are produced from the thermal decomposition of KClO3(s)which produces 50.0 mL of O2(g)at 25°C and 1.00 atm pressure according to the chemical equation shown below?
2 KClO3(s)→ 2 KCl(s)+ 3 O2(g)?

Accepted Answer

A)  0. 102 g 
B)  0. 152 g 
C)  0. 167 g 
D)  0. 304 g 
A)  0. 102 g 
B)  0. 152 g 
C)  0. 167 g 
D)  0. 304 g

Question 19

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)

Accepted Answer

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 
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

Question 20

A mixture of 0.220 moles CO,0.350 moles H2 and 0.640 moles He has a total pressure of 2.95 atm.What is the pressure of H2?

Accepted Answer

A)  1.17 atm 
B)  0.853 atm 
C)  1.03 atm 
D)  0.969 atm 
E)  0.649 atm 
A)  1.17 atm 
B)  0.853 atm 
C)  1.03 atm 
D)  0.969 atm 
E)  0.649 atm

Exam 11: Gases

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

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?

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?

The concentration of carbon monoxide in a sample of air is 9.2 ppm.There are ________ molecules of CO in 1.00 L of this air at 755 torr and 23°C.

Calculate the ratio of effusion rates of Cl2 to O2.

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?

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?

Which of the following gas samples would be most likely to behave ideally under the stated conditions?

Given the equation C2H6(g)+ O2(g)→ CO2(g)+ H2O(g)(not balanced),determine the number of liters of O2 consumed at STP when 270.0 grams of C2H6 is burned.

An instrument used to measure atmospheric pressure is called a

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 1.44-g sample of an unknown pure gas occupies a volume of 0.335 L at a pressure of and a temperature of 100.0°C.The unknown gas is

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

Given three cylinders containing O2 gas at the same volume and pressure.Cylinder A is at -15°C,cylinder B is at -5°F,cylinder C is at 255 K.Which cylinder contains the largest mass of oxygen?

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?

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

How many grams of KCl(s)are produced from the thermal decomposition of KClO3(s)which produces 50.0 mL of O2(g)at 25°C and 1.00 atm pressure according to the chemical equation shown below? 2 KClO3(s)→ 2 KCl(s)+ 3 O2(g)?

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 mixture of 0.220 moles CO,0.350 moles H2 and 0.640 moles He has a total pressure of 2.95 atm.What is the pressure of H2?

Essentials: Units, Measurements, and Problem Solving

Atoms

The Quantum Mechanical Model of the Atom

Periodic Properties of the Elements

Molecules and Compounds

Chemical Bonding I

Chemical Bonding Ii

Chemical Reactions and Chemical Quantities

Introduction to Solutions and Aqueous Reactions

Thermochemistry

Liquids, Solids, and Intermolecular Forces

Crystalline Solids and Modern Materials

Solutions

Chemical Kinetics

Chemical Equilibrium

Acids and Bases

Aqueous Ionic Equilibrium

Free Energy and Thermodynamics

Electrochemistry

Radioactivity and Nuclear Chemistry

Organic Chemistry

Transition Metals and Coordination Compounds

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 6.32 g of Al reacts with excess NaOH?

Calculate the ratio of effusion rates of Cl₂ to O₂.

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?

Given the equation C₂H₆(g)+ O₂(g)→ CO₂(g)+ H₂O(g)(not balanced),determine the number of liters of O₂ consumed at STP when 270.0 grams of C₂H₆ is burned.

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?

Given three cylinders containing O₂ gas at the same volume and pressure.Cylinder A is at -15°C,cylinder B is at -5°F,cylinder C is at 255 K.Which cylinder contains the largest mass of oxygen?

How many grams of KCl(s)are produced from the thermal decomposition of KClO₃(s)which produces 50.0 mL of O₂(g)at 25°C and 1.00 atm pressure according to the chemical equation shown below? 2 KClO₃(s)→ 2 KCl(s)+ 3 O₂(g)?

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 mixture of 0.220 moles CO,0.350 moles H₂ and 0.640 moles He has a total pressure of 2.95 atm.What is the pressure of H₂?