Question 1

How does formula mass differ from atomic mass?

Accepted Answer

A) They represent the same thing. 
B) The formula mass of a substance is the sum of the atomic masses of the elements is its chemical formula. The atomic mass is the mass of a single atom. 
C) The atomic mass of a substance is the sum of the formula masses of the elements is its chemical formula. The atomic mass is the mass of a single atom. 
D) The formula mass is the mass of the chemical formula and the atomic mass is the mass of the molecule. 
A) They represent the same thing. 
B) The formula mass of a substance is the sum of the atomic masses of the elements is its chemical formula. The atomic mass is the mass of a single atom. 
C) The atomic mass of a substance is the sum of the formula masses of the elements is its chemical formula. The atomic mass is the mass of a single atom. 
D) The formula mass is the mass of the chemical formula and the atomic mass is the mass of the molecule.

Question 2

Four units of monoatomic substance A combines with one unit diatomic substance B to make the triatomic substance C. Two units of triatomic substance C combine with one unit of diatomic substance B to make substance D. Place the letter of each substance next to the symbol that best describes its atomic or molecular structure.

Accepted Answer

A) A, D, B, C 
B) C, A, B, D 
C) D, B, A, C 
D) B, D, A, C 
A) A, D, B, C 
B) C, A, B, D 
C) D, B, A, C 
D) B, D, A, C

Question 3

Why does a glowing splint of wood burn only slowly in air, but rapidly in a burst of flames when placed in pure oxygen?

Accepted Answer

A) There is a greater number of collisions between the wood and oxygen molecules. 
B) Oxygen is a flammable gas. 
C) Pure oxygen is able to absorb carbon dioxide at a faster rate. 
D) A glowing wood splint is actually extinguished within pure oxygen because there's no room for the smoke to expand. 
A) There is a greater number of collisions between the wood and oxygen molecules. 
B) Oxygen is a flammable gas. 
C) Pure oxygen is able to absorb carbon dioxide at a faster rate. 
D) A glowing wood splint is actually extinguished within pure oxygen because there's no room for the smoke to expand.

Question 4

How many molecules of aspirin (formula mass aspirin = 180.0 amu)are there in a 0.250-gram sample?

Accepted Answer

A) 6.02 ×   
B) 8.36 ×   
C) 1.51 ×   
D) More information is needed. 
A) 6.02 ×   
B) 8.36 ×   
C) 1.51 ×   
D) More information is needed.

Question 5

If the following graphs are for the same reaction, which one is most likely the one with an added catalyst?

Accepted Answer

A) a 
B) b 
C) c 
D) d 
E) All have had catalyst added. 
A) a 
B) b 
C) c 
D) d 
E) All have had catalyst added.

Question 6

Which has the greatest number of molecules?

Accepted Answer

A) 28 g of nitrogen,   
B) 32 g of oxygen,   
C) 32 g of methane, C   
D) 38 g of fluorine,   
A) 28 g of nitrogen,   
B) 32 g of oxygen,   
C) 32 g of methane, C   
D) 38 g of fluorine,

Question 7

Small samples of oxygen gas needed in the laboratory can be generated by any number of simple chemical reactions, such as 2 KCl   (s)→ 2 KCl (s)+ 3   (g)
What mass of oxygen (in grams)is produced when 122.6 g of KCl   (formula mass = 122.6 amu)takes part in this reaction?

Accepted Answer

A) 32.00 grams 
B) 48.00 grams 
C) 96.00 grams 
D) More information is needed. 
A) 32.00 grams 
B) 48.00 grams 
C) 96.00 grams 
D) More information is needed.

Question 8

Balance the following chemical equation. ____ N2 + ____ H2 → ____ NH3

Accepted Answer

A) 1, 3, 2 
B) 1, 2, 3 
C) 3, 2, 1 
D) 2, 6, 4 
E) 1/2, 3/2, 1 
A) 1, 3, 2 
B) 1, 2, 3 
C) 3, 2, 1 
D) 2, 6, 4 
E) 1/2, 3/2, 1

Question 9

What is the environmentally unfriendly component of chlorinated fluorocarbons that ultimately damages ozone?

Accepted Answer

A) chlorine atoms 
B) fluorine atoms 
C) carbon atoms 
D) molecular fragments of carbon and fluorine 
E) all of the above 
A) chlorine atoms 
B) fluorine atoms 
C) carbon atoms 
D) molecular fragments of carbon and fluorine 
E) all of the above

Question 10

The reactants shown schematically below represent iron oxide,     and carbon monoxide, CO. Which of the following is the correct full balanced chemical equation for what is depicted?

Accepted Answer

A)      + 3 CO → 2 Fe + 3   
B)      + 3 CO → 3 FeO + 2 C 
C)      + 3 CO → 3 Fe   + 2C 
D)        + 3 CO → 2 Fe + 3   O 
A)      + 3 CO → 2 Fe + 3   
B)      + 3 CO → 3 FeO + 2 C 
C)      + 3 CO → 3 Fe   + 2C 
D)        + 3 CO → 2 Fe + 3   O

Question 11

Use the bond energies below to determine whether the following reaction is exothermic or endothermic:   H-H (bond energy: 436 kJ/mol) Cl-Cl (bond energy: 243 kJ/mol)
H-Cl (bond energy: 431 kJ/mol)

Accepted Answer

A) Exothermic with more than 50 kJ of energy released. 
B) Endothermic with more than 50 kJ of energy absorbed. 
C) Exothermic with less than 50 kJ of energy released. 
D) Endothermic with less than 50 kJ of energy absorbed. 
A) Exothermic with more than 50 kJ of energy released. 
B) Endothermic with more than 50 kJ of energy absorbed. 
C) Exothermic with less than 50 kJ of energy released. 
D) Endothermic with less than 50 kJ of energy absorbed.

Question 12

Ozone, O3, is ________.

Accepted Answer

A) a pollutant 
B) a naturally occurring compound 
C) an elemental material 
D) all of the above 
A) a pollutant 
B) a naturally occurring compound 
C) an elemental material 
D) all of the above

Question 13

Which of the following reaction energies is the most endothermic?

Accepted Answer

A) 540 kJ/mole 
B) -540 kJ/mole 
C) 125 kj/mole 
D) -125 kJ/mole 
E) not enough information given 
A) 540 kJ/mole 
B) -540 kJ/mole 
C) 125 kj/mole 
D) -125 kJ/mole 
E) not enough information given

Question 14

Which of the above reactions would proceed the slowest?

Accepted Answer

A) a 
B) b 
C) c 
D) all proceed at same rate 
E) not enough information given 
A) a 
B) b 
C) c 
D) all proceed at same rate 
E) not enough information given

Question 15

Which has the greater mass, 1.204 ×   molecules of molecular hydrogen,   , or 1.204 ×   molecules of water,   O?

Accepted Answer

A) 1.204 ×   molecules of molecular hydrogen has a greater mass than 1.204 ×   molecules of water 
B) 1.204 ×   molecules of water has a greater mass than 1.204 ×   molecules of molecular hydrogen. 
C) The mass of this many molecules of water and molecules are molecular hydrogen are the same. 
D) Not enough information is provided. 
A) 1.204 ×   molecules of molecular hydrogen has a greater mass than 1.204 ×   molecules of water 
B) 1.204 ×   molecules of water has a greater mass than 1.204 ×   molecules of molecular hydrogen. 
C) The mass of this many molecules of water and molecules are molecular hydrogen are the same. 
D) Not enough information is provided.

Question 16

Which of the following statements about catalysts is NOT true?

Accepted Answer

A) A catalyst alters the rate of a chemical reaction. 
B) A catalyst can be consumed in a reaction as long as it is regenerated. 
C) A catalyst can be used to speed up slow reactions. 
D) A catalyst does not change the energy of the reactants or the products. 
E) All of the above are true. 
A) A catalyst alters the rate of a chemical reaction. 
B) A catalyst can be consumed in a reaction as long as it is regenerated. 
C) A catalyst can be used to speed up slow reactions. 
D) A catalyst does not change the energy of the reactants or the products. 
E) All of the above are true.

Question 17

What are the formula masses of water,   O; propene,     ; and 2-propanol,     O?

Accepted Answer

A) water: 18 amu; propene: 40 amu; 2-propanol: 58 amu 
B) water: 18 amu; propene: 42 amu; 2-propanol: 62 amu 
C) water: 18 amu; propene: 42 amu; 2-propanol: 60 amu 
D) water: 18 amu; propene: 44 amu; 2-propanol: 64 amu 
A) water: 18 amu; propene: 40 amu; 2-propanol: 58 amu 
B) water: 18 amu; propene: 42 amu; 2-propanol: 62 amu 
C) water: 18 amu; propene: 42 amu; 2-propanol: 60 amu 
D) water: 18 amu; propene: 44 amu; 2-propanol: 64 amu

Question 18

Which is greater: 1.01 amu of hydrogen or 1.01 grams of hydrogen?

Accepted Answer

A) 1.01 amu of hydrogen is greater than 1.01 grams of hydrogen. 
B) 1.01 grams of hydrogen is greater than 1.01 amu of hydrogen 
C) 1.01 grams of hydrogen and 1.01 amu of hydrogen have the same mass. 
D) Not enough information information is provided. 
A) 1.01 amu of hydrogen is greater than 1.01 grams of hydrogen. 
B) 1.01 grams of hydrogen is greater than 1.01 amu of hydrogen 
C) 1.01 grams of hydrogen and 1.01 amu of hydrogen have the same mass. 
D) Not enough information information is provided.

Question 19

A catalytic converter increases the amount of carbon dioxide emitted by an automobile. Is this good news or bad news?

Accepted Answer

A) bad news because carbon dioxide contributes to global warming 
B) good news because plants thrive on carbon dioxide 
C) bad news because the carbon dioxide contributes to acid rain 
D) good news because it means more noxious chemicals are not being emitted 
A) bad news because carbon dioxide contributes to global warming 
B) good news because plants thrive on carbon dioxide 
C) bad news because the carbon dioxide contributes to acid rain 
D) good news because it means more noxious chemicals are not being emitted

Question 20

Two amu equals how many grams? (1 amu = 1.661 × 10-24 g)

Accepted Answer

A) 2 grams 
B) 1.661 ×   grams 
C) 3.322 ×   grams 
D) 1.204 ×   grams 
A) 2 grams 
B) 1.661 ×   grams 
C) 3.322 ×   grams 
D) 1.204 ×   grams

How does formula mass differ from atomic mass?

Why does a glowing splint of wood burn only slowly in air, but rapidly in a burst of flames when placed in pure oxygen?

How many molecules of aspirin (formula mass aspirin = 180.0 amu)are there in a 0.250-gram sample?

If the following graphs are for the same reaction, which one is most likely the one with an added catalyst?

Which has the greatest number of molecules?

Small samples of oxygen gas needed in the laboratory can be generated by any number of simple chemical reactions, such as 2 KCl (s)→ 2 KCl (s)+ 3 (g) What mass of oxygen (in grams)is produced when 122.6 g of KCl (formula mass = 122.6 amu)takes part in this reaction?

Balance the following chemical equation. N₂ + H₂ → NH₃

What is the environmentally unfriendly component of chlorinated fluorocarbons that ultimately damages ozone?

The reactants shown schematically below represent iron oxide, and carbon monoxide, CO. Which of the following is the correct full balanced chemical equation for what is depicted?

Use the bond energies below to determine whether the following reaction is exothermic or endothermic: H-H (bond energy: 436 kJ/mol) Cl-Cl (bond energy: 243 kJ/mol) H-Cl (bond energy: 431 kJ/mol)

Ozone, O₃, is ________.

Which of the following reaction energies is the most endothermic?

Which of the above reactions would proceed the slowest?

Which has the greater mass, 1.204 × molecules of molecular hydrogen, , or 1.204 × molecules of water, O?

Which of the following statements about catalysts is NOT true?

What are the formula masses of water, O; propene, ; and 2-propanol, O?

Which is greater: 1.01 amu of hydrogen or 1.01 grams of hydrogen?

A catalytic converter increases the amount of carbon dioxide emitted by an automobile. Is this good news or bad news?

Two amu equals how many grams? (1 amu = 1.661 × 10^-24 g)

About Science

Particles of Matter

Elements of Chemistry

Subatomic Particles

The Atomic Nucleus

How Atoms Bond

How Molecules Mix

How Water Behaves

Acids and Bases in Our Environment

Oxidations and Reductions Charge the World

Organic Compounds

Nutrients of Life

Medicinal Chemistry

Optimizing Food Production

Protection Water and Air Resources

Capturing Energy

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Exam 9: How Chemicals React

How does formula mass differ from atomic mass?

Why does a glowing splint of wood burn only slowly in air, but rapidly in a burst of flames when placed in pure oxygen?

How many molecules of aspirin (formula mass aspirin = 180.0 amu)are there in a 0.250-gram sample?

If the following graphs are for the same reaction, which one is most likely the one with an added catalyst?

Which has the greatest number of molecules?

Small samples of oxygen gas needed in the laboratory can be generated by any number of simple chemical reactions, such as 2 KCl (s)→ 2 KCl (s)+ 3 (g) What mass of oxygen (in grams)is produced when 122.6 g of KCl (formula mass = 122.6 amu)takes part in this reaction?

Balance the following chemical equation. ____ N2 + ____ H2 → ____ NH3

What is the environmentally unfriendly component of chlorinated fluorocarbons that ultimately damages ozone?

The reactants shown schematically below represent iron oxide, and carbon monoxide, CO. Which of the following is the correct full balanced chemical equation for what is depicted?

Use the bond energies below to determine whether the following reaction is exothermic or endothermic: H-H (bond energy: 436 kJ/mol) Cl-Cl (bond energy: 243 kJ/mol) H-Cl (bond energy: 431 kJ/mol)

Ozone, O3, is ________.

Which of the following reaction energies is the most endothermic?

Which of the above reactions would proceed the slowest?

Which has the greater mass, 1.204 × molecules of molecular hydrogen, , or 1.204 × molecules of water, O?

Which of the following statements about catalysts is NOT true?

What are the formula masses of water, O; propene, ; and 2-propanol, O?

Which is greater: 1.01 amu of hydrogen or 1.01 grams of hydrogen?

A catalytic converter increases the amount of carbon dioxide emitted by an automobile. Is this good news or bad news?

Two amu equals how many grams? (1 amu = 1.661 × 10-24 g)

About Science

Particles of Matter

Elements of Chemistry

Subatomic Particles

The Atomic Nucleus

How Atoms Bond

How Molecules Mix

How Water Behaves

Acids and Bases in Our Environment

Oxidations and Reductions Charge the World

Organic Compounds

Nutrients of Life

Medicinal Chemistry

Optimizing Food Production

Protection Water and Air Resources

Capturing Energy

Filters

Balance the following chemical equation. N₂ + H₂ → NH₃

Ozone, O₃, is ________.

Two amu equals how many grams? (1 amu = 1.661 × 10^-24 g)