Question 1

A chemical reaction that can proceed in either direction is called a _______.

Accepted Answer

The answer of A chemical reaction that can proceed in...

Question 2

The reactivity of an atom arises from the

Accepted Answer

A)  energy difference between the s and p orbitals. 
B)  potential energy of the outermost shell. 
C)  average distance of the outermost shell from the nucleus. 
D)  sum of the potential energies of all electron shells. 
E)  existence of unpaired electrons in the outermost shell. 
A)  energy difference between the s and p orbitals. 
B)  potential energy of the outermost shell. 
C)  average distance of the outermost shell from the nucleus. 
D)  sum of the potential energies of all electron shells. 
E)  existence of unpaired electrons in the outermost shell.

Question 3

Which of the following statements about the difference between ionic bonds and covalent bonds is true?

Accepted Answer

A)  An ionic bond is stronger. 
B)  Electron sharing is more equal in the covalent bond. 
C)  An ionic bond occurs more often in aqueous solutions. 
D)  An ionic bond occurs only in acids. 
E)  A covalent bond occurs only in nonpolar molecules. 
A)  An ionic bond is stronger. 
B)  Electron sharing is more equal in the covalent bond. 
C)  An ionic bond occurs more often in aqueous solutions. 
D)  An ionic bond occurs only in acids. 
E)  A covalent bond occurs only in nonpolar molecules.

Question 4

H2SO4 can ionize to yield two H+ ions and one SO42- ion. H2SO4 is therefore

Accepted Answer

A)  molar. 
B)  a base. 
C)  a buffer. 
D)  a solution. 
E)  an acid. 
A)  molar. 
B)  a base. 
C)  a buffer. 
D)  a solution. 
E)  an acid.

Question 5

Which of the following statements about atoms is true?

Accepted Answer

A)  The negative charge of an electron is larger than the positive charge of a proton. This is the reason that there are usually more protons than electrons in an atom. 
B)  Neutrons add mass to an atom without influencing other properties. 
C)  When the number of protons equals the number of electrons, an atom has a neutral charge. 
D)  Atoms of an element are radioactive whenever they vary in their number of neutrons. 
E)  The energy level of electrons is higher in shells close to the nucleus. 
A)  The negative charge of an electron is larger than the positive charge of a proton. This is the reason that there are usually more protons than electrons in an atom. 
B)  Neutrons add mass to an atom without influencing other properties. 
C)  When the number of protons equals the number of electrons, an atom has a neutral charge. 
D)  Atoms of an element are radioactive whenever they vary in their number of neutrons. 
E)  The energy level of electrons is higher in shells close to the nucleus.

Question 6

The role of a buffer is to

Accepted Answer

A)  allow the pH of a solution to vary widely. 
B)  make a solution basic. 
C)  maintain pH homeostasis. 
D)  disrupt pH homeostasis. 
E)  make a solution more acidic. 
A)  allow the pH of a solution to vary widely. 
B)  make a solution basic. 
C)  maintain pH homeostasis. 
D)  disrupt pH homeostasis. 
E)  make a solution more acidic.

Question 7

One mole of a substance contains 6.02 $\times$ 1023 molecules. This number is known as _______.

Accepted Answer

The answer of One mole of a substance contains 6.02...

Question 8

Isotopes of an element

Accepted Answer

A)  are always unstable and radioactive. 
B)  have different numbers of protons. 
C)  have the same atomic weight. 
D)  have different numbers of neutrons. 
E)  have different numbers of electrons. 
A)  are always unstable and radioactive. 
B)  have different numbers of protons. 
C)  have the same atomic weight. 
D)  have different numbers of neutrons. 
E)  have different numbers of electrons.

Question 9

Hydrophobic interactions

Accepted Answer

A)  are stronger than hydrogen bonds. 
B)  are stronger than covalent bonds. 
C)  can hold two ions together. 
D)  can hold two nonpolar molecules together. 
E)  are responsible for the surface tension of water. 
A)  are stronger than hydrogen bonds. 
B)  are stronger than covalent bonds. 
C)  can hold two ions together. 
D)  can hold two nonpolar molecules together. 
E)  are responsible for the surface tension of water.

Question 10

Chemical bonds formed by electrical attractions are

Accepted Answer

A)  covalent bonds. 
B)  ionic bonds. 
C)  hydrogen bonds. 
D)  van der Waals forces. 
E)  Both b and c 
A)  covalent bonds. 
B)  ionic bonds. 
C)  hydrogen bonds. 
D)  van der Waals forces. 
E)  Both b and c

Question 11

Which of the following are most likely to be miscible (soluble in each other)?

Accepted Answer

A)  Octane and water 
B)  Water and methanol 
C)  Amino acid and octane 
D)  Water and octane 
E)  Amino acid and water 
A)  Octane and water 
B)  Water and methanol 
C)  Amino acid and octane 
D)  Water and octane 
E)  Amino acid and water

Question 12

A human hair is found to have a high ratio of 18O to 16O. From this information it can be assumed that

Accepted Answer

A)  the person is suffering from a chronic disease such as diabetes. 
B)  the person has experienced prolonged exposure to radioactivity. 
C)  the person lives in a region where "heavy" water is consumed. 
D)  the person regularly uses a protein-rich hair conditioner. 
E)  the person eats a diet high in cholesterol-rich meat. 
A)  the person is suffering from a chronic disease such as diabetes. 
B)  the person has experienced prolonged exposure to radioactivity. 
C)  the person lives in a region where "heavy" water is consumed. 
D)  the person regularly uses a protein-rich hair conditioner. 
E)  the person eats a diet high in cholesterol-rich meat.

Question 13

Which of the diagrams below is the Bohr model for magnesium (Mg)?

Accepted Answer

A)   
B)   
C)   
D)   
E)   
A)   
B)   
C)   
D)   
E)

Question 14

Which of the following statements best describes the difference between an element and a molecule?

Accepted Answer

A)  An element is composed of atoms; a molecule is not. 
B)  An element is composed of only one kind of atom; molecules can be composed of more than one kind of atom. 
C)  An element is unstable; molecules are stable. 
D)  Elements always have lower atomic weights than molecules. 
E)  Elements exist in nature only as parts of molecules. 
A)  An element is composed of atoms; a molecule is not. 
B)  An element is composed of only one kind of atom; molecules can be composed of more than one kind of atom. 
C)  An element is unstable; molecules are stable. 
D)  Elements always have lower atomic weights than molecules. 
E)  Elements exist in nature only as parts of molecules.

Question 15

Two carbon atoms held together in a double covalent bond share _______ electron(s).

Accepted Answer

A)  one 
B)  two 
C)  four 
D)  six 
E)  eight 
A)  one 
B)  two 
C)  four 
D)  six 
E)  eight

Question 16

The hydrogen bond between two water molecules arises because water is

Accepted Answer

A)  polar. 
B)  nonpolar. 
C)  a liquid. 
D)  a small molecule. 
E)  hydrophobic. 
A)  polar. 
B)  nonpolar. 
C)  a liquid. 
D)  a small molecule. 
E)  hydrophobic.

Question 17

Surface tension and capillary action occur in water because it

Accepted Answer

A)  is wet. 
B)  is dense. 
C)  has hydrogen bonds. 
D)  is nonpolar. 
E)  has ionic bonds. 
A)  is wet. 
B)  is dense. 
C)  has hydrogen bonds. 
D)  is nonpolar. 
E)  has ionic bonds.

Question 18

Hydrocarbons are _______ and _______, whereas salts are _______ and _______.

Accepted Answer

A)  nonpolar; hydrophobic; polar; hydrophilic 
B)  nonpolar; hydrophilic; polar; hydrophobic 
C)  polar; hydrophilic; nonpolar; hydrophobic 
D)  polar; hydrophobic; nonpolar ; hydrophilic 
E)  None of the above 
A)  nonpolar; hydrophobic; polar; hydrophilic 
B)  nonpolar; hydrophilic; polar; hydrophobic 
C)  polar; hydrophilic; nonpolar; hydrophobic 
D)  polar; hydrophobic; nonpolar ; hydrophilic 
E)  None of the above

Question 19

The molecular weight of water is 18.0154. One mole of water weighs _______ grams.

Accepted Answer

A)  9 
B)  18 
C)  20 
D)  36.031 
E)  6.023 $\times$ 1023 
A)  9 
B)  18 
C)  20 
D)  36.031 
E)  6.023 $\times$ 1023

Question 20

One mole of glucose (C6H12O6) weighs

Accepted Answer

A)  180 grams. 
B)  42 atomic mass units. 
C)  96 grams. 
D)  342 grams. 
E)  6.02 grams. 
A)  180 grams. 
B)  42 atomic mass units. 
C)  96 grams. 
D)  342 grams. 
E)  6.02 grams.

Exam 2: Small Molecules and the Chemistry of Life

A chemical reaction that can proceed in either direction is called a _______.

The reactivity of an atom arises from the

Which of the following statements about the difference between ionic bonds and covalent bonds is true?

H2SO4 can ionize to yield two H+ ions and one SO42- ion. H2SO4 is therefore

Which of the following statements about atoms is true?

The role of a buffer is to

One mole of a substance contains 6.02 ×\times× 1023 molecules. This number is known as _______.

Isotopes of an element

Hydrophobic interactions

Chemical bonds formed by electrical attractions are

Which of the following are most likely to be miscible (soluble in each other)?

A human hair is found to have a high ratio of 18O to 16O. From this information it can be assumed that

Which of the diagrams below is the Bohr model for magnesium (Mg)?

Which of the following statements best describes the difference between an element and a molecule?

Two carbon atoms held together in a double covalent bond share _______ electron(s).

The hydrogen bond between two water molecules arises because water is

Surface tension and capillary action occur in water because it

Hydrocarbons are _______ and _______, whereas salts are _______ and _______.

The molecular weight of water is 18.0154. One mole of water weighs _______ grams.

One mole of glucose (C6H12O6) weighs

Studying Life

Proteins, Carbohydrates, and Lipids

Nucleic Acids and the Origin of Life

Cells: the Working Units of Life

Cell Membranes

Cell Signaling and Communication

Energy, Enzymes, and Metabolism

Pathways That Harvest Chemical Energy

Photosynthesis: Energy From Sunlight

The Cell Cycle and Cell Division

Inheritance, Genes, and Chromosomes

Dna and Its Role in Heredity

From Dna to Protein: Gene Expression

Gene Mutation and Molecular Medicine

Regulation of Gene Expression

Genomes

Recombinent Dna and Biotechnology

Differential Gene Expression in Development

Development and Evolutionary Change

Evidence and Mechanisms of Evolution

Reconstructing and Using Phylogenies

Species and Their Formation

Evolution of Genes and Genomes

The History of Life on Earth

Bacteria and Archaea: the Prokaryotic Domains

The Origin and Diversification of Eukaryotes

Plants Without Seeds: From Water to Land

The Evolution of Seed Plants

Fungi: Recyclers, Pathogens, Parasites, and Plant Partners

Animal Origins and the Evolution of Body Plans

Protostome Animals

Deuterostome Animals

The Plant Body

Transport in Plants

Plant Nutrition

Regulation of Plant Growth

Reproduction in Flowering Plants

Plant Responses to Environmental Challenges

Physiology, Homeostasis, and Temperature Regulation

Animal Hormones

Immunology: Animal Defense Systems

Animal Reproduction

Animal Development

Neurons and Nervous Systems

Sensory Systems

The Mammalian Nervous System: Structure and Higher Function

Musculoskeletal Systems

Gas Exchange in Animals

Circulatory Systems

Nutrition, Digestion, and Absorption

Salt and Water Balance and Nitrogen

Animal Behavior

Ecology and the Distribution of Life

Population Ecology

Species Interaction and Coevolution

Community Ecology

Ecosystems and Global Ecology

Conservation Biology

Filters

H₂SO₄ can ionize to yield two H⁺ ions and one SO₄²^- ion. H₂SO₄ is therefore

One mole of a substance contains 6.02 $\times$ 10²³ molecules. This number is known as _______.

A human hair is found to have a high ratio of ¹⁸O to ¹⁶O. From this information it can be assumed that

Hydrocarbons are ___ and _, whereas salts are _ and ___.

One mole of glucose (C₆H₁₂O₆) weighs