Question 1

Ice melts spontaneously at room temperature, even though the process is endothermic. How is this possible?

Accepted Answer

A)  The change in thermal energy is small, so melting still obeys the second law of thermodynamics. 
B)  The first law of thermodynamics does not apply to phase changes such as melting. 
C)  Water has a very high specific heat. 
D)  There is a large increase in entropy. 
A)  The change in thermal energy is small, so melting still obeys the second law of thermodynamics. 
B)  The first law of thermodynamics does not apply to phase changes such as melting. 
C)  Water has a very high specific heat. 
D)  There is a large increase in entropy.

Question 2

Based on your knowledge of the polarity of water molecules, the solute molecule depicted here is most likely ________.

Accepted Answer

A)  positively charged 
B)  negatively charged 
C)  without charge 
D)  hydrophobic 
E)  nonpolar 
A)  positively charged 
B)  negatively charged 
C)  without charge 
D)  hydrophobic 
E)  nonpolar

Question 3

What results from the chemical reaction illustrated above? The reactants have no charge.

Accepted Answer

A)  a cation with a net charge of +1 and an anion with a net charge of +1 
B)  a cation with a net charge of −1 and an anion with a net charge of −1 
C)  a cation with a net charge of −1 and an anion with a net charge of +1 
D)  a cation with a net charge of +1 and an anion with a net charge of −1 
A)  a cation with a net charge of +1 and an anion with a net charge of +1 
B)  a cation with a net charge of −1 and an anion with a net charge of −1 
C)  a cation with a net charge of −1 and an anion with a net charge of +1 
D)  a cation with a net charge of +1 and an anion with a net charge of −1

Question 4

A solution contains 0.0000001 (10−7) moles of hydroxyl ions [OH−] per liter. Which of the following best describes this solution?

Accepted Answer

A)  acidic: H+ acceptor 
B)  basic: H+ acceptor 
C)  acidic: H+ donor 
D)  basic: H+ donor 
E)  neutral 
A)  acidic: H+ acceptor 
B)  basic: H+ acceptor 
C)  acidic: H+ donor 
D)  basic: H+ donor 
E)  neutral

Question 5

During chemical evolution, which of the following occurred in the molecules involved?

Accepted Answer

A)  Entropy decreased while potential energy increased. 
B)  Entropy increased while potential energy increased. 
C)  Entropy stayed constant while potential energy increased. 
A)  Entropy decreased while potential energy increased. 
B)  Entropy increased while potential energy increased. 
C)  Entropy stayed constant while potential energy increased.

Question 6

Which of the following is a property of liquid water? Liquid water ________.

Accepted Answer

A)  is less dense than ice 
B)  has a specific heat that is lower than that for most other substances 
C)  has a heat of vaporization that is higher than that for most other substances 
D)  is nonpolar 
A)  is less dense than ice 
B)  has a specific heat that is lower than that for most other substances 
C)  has a heat of vaporization that is higher than that for most other substances 
D)  is nonpolar

Question 7

How many electrons are involved in a single covalent bond?

Accepted Answer

A)  one 
B)  two 
C)  three 
D)  four 
A)  one 
B)  two 
C)  three 
D)  four

Question 8

Stanley Miller's 1953 experiments supported the hypothesis that ________.

Accepted Answer

A)  life on Earth arose from simple inorganic molecules 
B)  organic molecules can be synthesized abiotically under conditions that may have existed on early Earth 
C)  life on Earth arose from simple organic molecules, with energy from lightning and volcanoes 
D)  the conditions on early Earth were conducive to the origin of life 
E)  the conditions on early Earth were conducive to the abiotic synthesis of organic molecules 
A)  life on Earth arose from simple inorganic molecules 
B)  organic molecules can be synthesized abiotically under conditions that may have existed on early Earth 
C)  life on Earth arose from simple organic molecules, with energy from lightning and volcanoes 
D)  the conditions on early Earth were conducive to the origin of life 
E)  the conditions on early Earth were conducive to the abiotic synthesis of organic molecules

Question 9

What is the difference between covalent bonds and ionic bonds?

Accepted Answer

A)  Covalent bonds require carbon whereas ionic bonds do not. 
B)  Covalent bonds involve the sharing of pairs of electrons between atoms; ionic bonds involve the sharing of single electrons between atoms. 
C)  Covalent bonds involve the sharing of electrons between atoms; ionic bonds involve the electrical attraction between charged atoms. 
D)  Covalent bonds involve the sharing of electrons between atoms; ionic bonds involve the sharing of protons between charged atoms. 
E)  Covalent bonds involve the transfer of electrons between charged atoms; ionic bonds involve the sharing of electrons between atoms. 
A)  Covalent bonds require carbon whereas ionic bonds do not. 
B)  Covalent bonds involve the sharing of pairs of electrons between atoms; ionic bonds involve the sharing of single electrons between atoms. 
C)  Covalent bonds involve the sharing of electrons between atoms; ionic bonds involve the electrical attraction between charged atoms. 
D)  Covalent bonds involve the sharing of electrons between atoms; ionic bonds involve the sharing of protons between charged atoms. 
E)  Covalent bonds involve the transfer of electrons between charged atoms; ionic bonds involve the sharing of electrons between atoms.

Question 10

Nitrogen (N) is more electronegative than hydrogen (H). Which of the following is a correct statement about the atoms in ammonia (NH3)?

Accepted Answer

A)  Each hydrogen atom has a partial positive charge; the nitrogen atom has a partial negative charge. 
B)  Ammonia has an overall positive charge. 
C)  Ammonia has an overall negative charge. 
D)  The nitrogen atom has a partial positive charge; each hydrogen atom has a partial negative charge. 
E)  There are covalent bonds between the hydrogen atoms and polar bonds between each hydrogen atom and the nitrogen atom. 
A)  Each hydrogen atom has a partial positive charge; the nitrogen atom has a partial negative charge. 
B)  Ammonia has an overall positive charge. 
C)  Ammonia has an overall negative charge. 
D)  The nitrogen atom has a partial positive charge; each hydrogen atom has a partial negative charge. 
E)  There are covalent bonds between the hydrogen atoms and polar bonds between each hydrogen atom and the nitrogen atom.

Question 11

-Which drawing in the figure above depicts an atom with six valence electrons?

Accepted Answer

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

Question 12

A covalent bond is likely to be polar when ________.

Accepted Answer

A)  one of the atoms sharing electrons is more electronegative than the other atom 
B)  the two atoms sharing electrons are equally electronegative 
C)  carbon is one of the two atoms sharing electrons 
D)  one of the atoms has absorbed more energy than the other atom 
E)  the two atoms sharing electrons are the same elements 
A)  one of the atoms sharing electrons is more electronegative than the other atom 
B)  the two atoms sharing electrons are equally electronegative 
C)  carbon is one of the two atoms sharing electrons 
D)  one of the atoms has absorbed more energy than the other atom 
E)  the two atoms sharing electrons are the same elements

Question 13

About twenty-five of the 92 natural elements are known to be essential to life. Which 4 of these 25 elements make up approximately 96 percent of living matter?

Accepted Answer

A)  carbon, sodium, hydrogen, nitrogen 
B)  carbon, oxygen, phosphorus, hydrogen 
C)  oxygen, hydrogen, calcium, nitrogen 
D)  carbon, hydrogen, nitrogen, oxygen 
E)  carbon, oxygen, nitrogen, calcium 
A)  carbon, sodium, hydrogen, nitrogen 
B)  carbon, oxygen, phosphorus, hydrogen 
C)  oxygen, hydrogen, calcium, nitrogen 
D)  carbon, hydrogen, nitrogen, oxygen 
E)  carbon, oxygen, nitrogen, calcium

Question 14

Which of the following is the most spontaneous reaction? A reaction that is ________.

Accepted Answer

A)  slightly exothermic and leads to a slight increase in entropy 
B)  slightly endothermic and leads to a huge decrease in entropy 
C)  highly exothermic and leads to a huge decrease in entropy 
D)  slightly exothermic and leads to a huge increase in entropy 
A)  slightly exothermic and leads to a slight increase in entropy 
B)  slightly endothermic and leads to a huge decrease in entropy 
C)  highly exothermic and leads to a huge decrease in entropy 
D)  slightly exothermic and leads to a huge increase in entropy

Question 15

Which of the following effects can occur because of the high surface tension of water?

Accepted Answer

A)  Lakes cannot freeze solid in winter, despite low temperatures. 
B)  A raft spider can walk across the surface of a small pond. 
C)  Organisms can resist temperature changes, although they give off heat due to chemical reactions. 
D)  Sweat can evaporate from the skin, helping to keep people from overheating. 
E)  Water can flow upward from roots to the leaves in plants. 
A)  Lakes cannot freeze solid in winter, despite low temperatures. 
B)  A raft spider can walk across the surface of a small pond. 
C)  Organisms can resist temperature changes, although they give off heat due to chemical reactions. 
D)  Sweat can evaporate from the skin, helping to keep people from overheating. 
E)  Water can flow upward from roots to the leaves in plants.

Question 16

What is the pH of a solution with a hydroxyl ion (OH−) concentration of 10−12 M?

Accepted Answer

A)  pH 2 
B)  pH 4 
C)  pH 10 
D)  pH 12 
E)  pH 14 
A)  pH 2 
B)  pH 4 
C)  pH 10 
D)  pH 12 
E)  pH 14

Question 17

Why does ice float in liquid water?

Accepted Answer

A)  The high surface tension of liquid water keeps the ice on top. 
B)  The ionic bonds between the molecules in ice prevent the ice from sinking. 
C)  Ice always has air bubbles that keep it afloat. 
D)  Stable hydrogen bonds keep water molecules of ice farther apart than water molecules of liquid water. 
E)  The crystalline lattice of ice causes it to be denser than liquid water. 
A)  The high surface tension of liquid water keeps the ice on top. 
B)  The ionic bonds between the molecules in ice prevent the ice from sinking. 
C)  Ice always has air bubbles that keep it afloat. 
D)  Stable hydrogen bonds keep water molecules of ice farther apart than water molecules of liquid water. 
E)  The crystalline lattice of ice causes it to be denser than liquid water.

Question 18

Why is each element unique with respect to its chemical properties? Each element has a distinctive ________.

Accepted Answer

A)  atomic mass 
B)  number of electrons 
C)  number of protons 
D)  number of neutrons 
E)  radioactive property 
A)  atomic mass 
B)  number of electrons 
C)  number of protons 
D)  number of neutrons 
E)  radioactive property

Question 19

When the atoms involved in a covalent bond have the same electronegativity, what type of bond results?

Accepted Answer

A)  an ionic bond 
B)  a hydrogen bond 
C)  a nonpolar covalent bond 
D)  a polar covalent bond 
A)  an ionic bond 
B)  a hydrogen bond 
C)  a nonpolar covalent bond 
D)  a polar covalent bond

Exam 2: Water and Carbon: the Chemical Basis of Life

Ice melts spontaneously at room temperature, even though the process is endothermic. How is this possible?

Based on your knowledge of the polarity of water molecules, the solute molecule depicted here is most likely ________.

What results from the chemical reaction illustrated above? The reactants have no charge.

A solution contains 0.0000001 (10−7) moles of hydroxyl ions [OH−] per liter. Which of the following best describes this solution?

During chemical evolution, which of the following occurred in the molecules involved?

Which of the following is a property of liquid water? Liquid water ________.

How many electrons are involved in a single covalent bond?

Stanley Miller's 1953 experiments supported the hypothesis that ________.

What is the difference between covalent bonds and ionic bonds?

Nitrogen (N) is more electronegative than hydrogen (H). Which of the following is a correct statement about the atoms in ammonia (NH3)?

-Which drawing in the figure above depicts an atom with six valence electrons?

A covalent bond is likely to be polar when ________.

About twenty-five of the 92 natural elements are known to be essential to life. Which 4 of these 25 elements make up approximately 96 percent of living matter?

Which of the following is the most spontaneous reaction? A reaction that is ________.

Which of the following effects can occur because of the high surface tension of water?

What is the pH of a solution with a hydroxyl ion (OH−) concentration of 10−12 M?

Why does ice float in liquid water?

Why is each element unique with respect to its chemical properties? Each element has a distinctive ________.

When the atoms involved in a covalent bond have the same electronegativity, what type of bond results?

Biology and the Tree of Life

Protein Structure and Function

Nucleic Acids and the Rna World

An Introduction to Carbohydrates

Ecosystems and Global Ecology

Lipids, Membranes, and the First Cells

Inside the Cell

Energy and Enzymes: an Introduction to Metabolism

Cellular Respiration and Fermentation

Photosynthesis

Cellcell Interactions

The Cell Cycle

Meiosis

Mendel and the Gene

Dna and the Gene: Synthesis and Repair

How Genes Work

Transcription, Rna Processing, and Translation

Control of Gene Expression in Bacteria

Control of Gene Expression in Eukaryotes

The Molecular Revolution: Biotechnology and Beyond

Genes, Development, and Evolution

Evolution by Natural Selection

Evolutionary Processes

Speciation

Phylogenies and the History of Life

Bacteria and Archaea

Protists

Green Algae and Land Plants

Fungi

An Introduction to Animals

Protostome Animals

Deuterostome Animals

Viruses

Plant Form and Function

Water and Sugar Transport in Plants

Plant Nutrition

Plant Sensory Systems, Signals, and Responses

Plant Reproduction and Development

Animal Form and Function

Water and Electrolyte Balance in Animals

Animal Nutrition

Gas Exchange and Circulation

Animal Nervous Systems

Animal Sensory Systems

Animal Movement

Chemical Signals in Animals

Animal Reproduction and Development

The Immune System in Animals

An Introduction to Ecology

Behavioral Ecology

Population Ecology

Community Ecology

Biodiversity and Conservation Biology

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