Question 1

We can be sure that a mole of table sugar and a mole of vitamin C are equal in their

Accepted Answer

A)  mass in daltons. 
B)  mass in grams. 
C)  volume. 
D)  number of atoms. 
E)  number of molecules. 
A)  mass in daltons. 
B)  mass in grams. 
C)  volume. 
D)  number of atoms. 
E)  number of molecules.

Question 2

Buffers are substances that help resist shifts in pH by

Accepted Answer

A)  releasing H⁺ to a solution when acids are added. 
B)  donating H⁺ to a solution when bases are added. 
C)  releasing OH⁻ to a solution when bases are added. 
D)  accepting H⁺ from a solution when acids are added. 
E)  both donating H+ to a solution when bases are added, and accepting H+ when acids are added. 
A)  releasing H⁺ to a solution when acids are added. 
B)  donating H⁺ to a solution when bases are added. 
C)  releasing OH⁻ to a solution when bases are added. 
D)  accepting H⁺ from a solution when acids are added. 
E)  both donating H+ to a solution when bases are added, and accepting H+ when acids are added.

Question 3

If the cytoplasm of a cell is at pH 7, and the mitochondrial matrix is at pH 8, this means that

Accepted Answer

A)  the concentration of H+ ions is tenfold higher in the cytoplasm than in the mitochondrial matrix. 
B)  the concentration of H+ ions is tenfold higher in the mitochondrial matrix than in the cytoplasm. 
C)  the concentration of H+ ions in the cytoplasm is 7/8 the concentration in the mitochondrial matrix. 
D)  the mitochondrial matrix is more acidic than the cytoplasm. 
E)  the concentration of H+ ions in the cytoplasm is 8/7 the concentration in the mitochondrial matrix. 
A)  the concentration of H+ ions is tenfold higher in the cytoplasm than in the mitochondrial matrix. 
B)  the concentration of H+ ions is tenfold higher in the mitochondrial matrix than in the cytoplasm. 
C)  the concentration of H+ ions in the cytoplasm is 7/8 the concentration in the mitochondrial matrix. 
D)  the mitochondrial matrix is more acidic than the cytoplasm. 
E)  the concentration of H+ ions in the cytoplasm is 8/7 the concentration in the mitochondrial matrix.

Question 4

Which of the following solutions would require the greatest amount of base to be added to bring the solution to neutral pH?

Accepted Answer

A)  gastric juice at pH 2 
B)  vinegar at pH 3 
C)  tomato juice at pH 4 
D)  black coffee at pH 5 
E)  household bleach at pH 12 
A)  gastric juice at pH 2 
B)  vinegar at pH 3 
C)  tomato juice at pH 4 
D)  black coffee at pH 5 
E)  household bleach at pH 12

Question 5

Hydrophobic substances such as vegetable oil are

Accepted Answer

A)  nonpolar substances that repel water molecules. 
B)  nonpolar substances that have an attraction for water molecules. 
C)  polar substances that repel water molecules. 
D)  polar substances that have an affinity for water. 
E)  charged molecules that hydrogen-bond with water molecules. 
A)  nonpolar substances that repel water molecules. 
B)  nonpolar substances that have an attraction for water molecules. 
C)  polar substances that repel water molecules. 
D)  polar substances that have an affinity for water. 
E)  charged molecules that hydrogen-bond with water molecules.

Question 6

One of the buffers that contribute to pH stability in human blood is carbonic acid (H₂CO₃). Carbonic acid is a weak acid that, when placed in an aqueous solution, dissociates into a bicarbonate ion (HCO₃⁻ and a hydrogen ion (H⁺). Thus,
H₂CO₃ ↔ HCO₃⁻ + H⁺
If the pH of the blood increases, one would expect

Accepted Answer

A)  a decrease in the concentration of H₂CO₃ and an increase in the concentration of HCO₃⁻. 
B)  an increase in the concentration of H₂CO₃ and a decrease in the concentration of HCO₃⁻. 
C)  a decrease in the concentration of HCO₃⁻ and an increase in the concentration of H⁺. 
D)  an increase in the concentration of HCO₃⁻ and a decrease in the concentration of OH⁻. 
E)  a decrease in the concentration of HCO₃⁻ and an increase in the concentration of both H₂CO₃ and H⁺. 
A)  a decrease in the concentration of H₂CO₃ and an increase in the concentration of HCO₃⁻. 
B)  an increase in the concentration of H₂CO₃ and a decrease in the concentration of HCO₃⁻. 
C)  a decrease in the concentration of HCO₃⁻ and an increase in the concentration of H⁺. 
D)  an increase in the concentration of HCO₃⁻ and a decrease in the concentration of OH⁻. 
E)  a decrease in the concentration of HCO₃⁻ and an increase in the concentration of both H₂CO₃ and H⁺.

Question 7

Which of the following ionizes completely in solution and is considered to be a strong base (alkali)?

Accepted Answer

A)  NaCl 
B)  HCl 
C)  NH₃ 
D)  H₂CO₃ 
E)  NaOH 
A)  NaCl 
B)  HCl 
C)  NH₃ 
D)  H₂CO₃ 
E)  NaOH

Question 8

A 0.01 M solution of a substance has a pH of 2. What can you conclude about this substance?

Accepted Answer

A)  It is a strong acid that ionizes completely in water. 
B)  It is a strong base that ionizes completely in water. 
C)  It is a weak acid. 
D)  It is a weak base. 
E)  It is neither an acid nor a base. 
A)  It is a strong acid that ionizes completely in water. 
B)  It is a strong base that ionizes completely in water. 
C)  It is a weak acid. 
D)  It is a weak base. 
E)  It is neither an acid nor a base.

Question 9

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)  Hydrogen bonds stabilize and keep the molecules of ice farther apart than the 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)  Hydrogen bonds stabilize and keep the molecules of ice farther apart than the water molecules of liquid water. 
E)  The crystalline lattice of ice causes it to be denser than liquid water.

Question 10

Which of these molecules would be soluble in water?

Accepted Answer

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

Question 11

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 12

Carbon dioxide (CO₂)is readily soluble in water, according to the equation CO₂ + H₂O ↔ H₂CO₃. Carbonic acid (H₂CO₃)is a weak acid. Respiring cells release CO₂ into the bloodstream. What will be the effect on pH of blood as that blood first comes in contact with respiring cells?

Accepted Answer

A)  Blood pH will decrease slightly. 
B)  Blood pH will increase slightly. 
C)  Blood pH will remain unchanged. 
D)  Blood pH will first increase, then decrease as CO₂ combines with hemoglobin. 
E)  Blood pH will first decrease, then increase sharply as CO₂ combines with hemoglobin. 
A)  Blood pH will decrease slightly. 
B)  Blood pH will increase slightly. 
C)  Blood pH will remain unchanged. 
D)  Blood pH will first increase, then decrease as CO₂ combines with hemoglobin. 
E)  Blood pH will first decrease, then increase sharply as CO₂ combines with hemoglobin.

Question 13

A strong acid like HCl

Accepted Answer

A)  ionizes completely in an aqueous solution. 
B)  increases the pH when added to an aqueous solution. 
C)  reacts with strong bases to create a buffered solution. 
D)  is a strong buffer at low pH. 
E)  both ionizes completely in aqueous solutions and is a strong buffer at low pH. 
A)  ionizes completely in an aqueous solution. 
B)  increases the pH when added to an aqueous solution. 
C)  reacts with strong bases to create a buffered solution. 
D)  is a strong buffer at low pH. 
E)  both ionizes completely in aqueous solutions and is a strong buffer at low pH.

Question 14

The partial negative charge in a molecule of water occurs because

Accepted Answer

A)  the oxygen atom acquires an additional electron. 
B)  the electrons shared between the oxygen and hydrogen atoms spend more time around the oxygen atom nucleus than around the hydrogen atom nucleus. 
C)  the oxygen atom has two pairs of electrons in its valence shell that are not neutralized by hydrogen atoms. 
D)  the oxygen atom forms hybrid orbitals that distribute electrons unequally around the oxygen nucleus. 
E)  one of the hydrogen atoms donates an electron to the oxygen atom. 
A)  the oxygen atom acquires an additional electron. 
B)  the electrons shared between the oxygen and hydrogen atoms spend more time around the oxygen atom nucleus than around the hydrogen atom nucleus. 
C)  the oxygen atom has two pairs of electrons in its valence shell that are not neutralized by hydrogen atoms. 
D)  the oxygen atom forms hybrid orbitals that distribute electrons unequally around the oxygen nucleus. 
E)  one of the hydrogen atoms donates an electron to the oxygen atom.

Question 15

-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 16

You have two beakers. One contains a solution of HCl at pH = 1.0. The other contains a solution of NaOH at pH = 13. Into a third beaker, you slowly and cautiously pour 20 mL of the HCl and 20 mL of the NaOH. After complete stirring, the pH of the mixture will be

Accepted Answer

A)  2.0. 
B)  12.0. 
C)  7.0. 
D)  5.0. 
E)  9.0. 
A)  2.0. 
B)  12.0. 
C)  7.0. 
D)  5.0. 
E)  9.0.

Question 17

Equal volumes (5 mL)of vinegar from a freshly opened bottle are added to each of the following solutions. After complete mixing, which of the mixtures will have the highest pH?

Accepted Answer

A)  100 mL of pure water 
B)  100 mL of freshly brewed coffee 
C)  100 mL of household cleanser containing 0.5 M ammonia 
D)  100 mL of freshly squeezed orange juice 
E)  100 mL of tomato juice 
A)  100 mL of pure water 
B)  100 mL of freshly brewed coffee 
C)  100 mL of household cleanser containing 0.5 M ammonia 
D)  100 mL of freshly squeezed orange juice 
E)  100 mL of tomato juice

Question 18

What is the pH of a 1 millimolar NaOH solution?

Accepted Answer

A)  pH 3 
B)  pH 8 
C)  pH 9 
D)  pH 10 
E)  pH 11 
A)  pH 3 
B)  pH 8 
C)  pH 9 
D)  pH 10 
E)  pH 11

Question 19

Why does evaporation of water from a surface cause cooling of the surface?

Accepted Answer

A)  The breaking of bonds between water molecules absorbs heat. 
B)  The water molecules with the most heat energy evaporate more readily. 
C)  The solute molecules left behind absorb heat. 
D)  Water molecules absorb heat from the surface in order to acquire enough energy to evaporate. 
E)  The expansion of water vapor extracts heat from the surface. 
A)  The breaking of bonds between water molecules absorbs heat. 
B)  The water molecules with the most heat energy evaporate more readily. 
C)  The solute molecules left behind absorb heat. 
D)  Water molecules absorb heat from the surface in order to acquire enough energy to evaporate. 
E)  The expansion of water vapor extracts heat from the surface.

Question 20

Assume that acid rain has lowered the pH of a particular lake to pH 4.0. What is the hydroxyl ion concentration of this lake?

Accepted Answer

A)  1 × 10⁻¹⁰ mol of hydroxyl ion per liter of lake water 
B)  1 × 10⁻⁴ mol of hydroxyl ion per liter of lake water 
C)  10.0 M with regard to hydroxyl ion concentration 
D)  4.0 M with regard to hydroxyl ion concentration 
E)  1 × 10⁻⁴ mol of hydroxyl ion per liter of lake water and 4.0 M with regard to hydrogen ion concentration 
A)  1 × 10⁻¹⁰ mol of hydroxyl ion per liter of lake water 
B)  1 × 10⁻⁴ mol of hydroxyl ion per liter of lake water 
C)  10.0 M with regard to hydroxyl ion concentration 
D)  4.0 M with regard to hydroxyl ion concentration 
E)  1 × 10⁻⁴ mol of hydroxyl ion per liter of lake water and 4.0 M with regard to hydrogen ion concentration

Exam 3: Water and Life

We can be sure that a mole of table sugar and a mole of vitamin C are equal in their

Buffers are substances that help resist shifts in pH by

If the cytoplasm of a cell is at pH 7, and the mitochondrial matrix is at pH 8, this means that

Which of the following solutions would require the greatest amount of base to be added to bring the solution to neutral pH?

Hydrophobic substances such as vegetable oil are

Which of the following ionizes completely in solution and is considered to be a strong base (alkali)?

A 0.01 M solution of a substance has a pH of 2. What can you conclude about this substance?

Why does ice float in liquid water?

Which of these molecules would be soluble in water?

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

Carbon dioxide (CO₂)is readily soluble in water, according to the equation CO₂ + H₂O ↔ H₂CO₃. Carbonic acid (H₂CO₃)is a weak acid. Respiring cells release CO₂ into the bloodstream. What will be the effect on pH of blood as that blood first comes in contact with respiring cells?

A strong acid like HCl

The partial negative charge in a molecule of water occurs because

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

You have two beakers. One contains a solution of HCl at pH = 1.0. The other contains a solution of NaOH at pH = 13. Into a third beaker, you slowly and cautiously pour 20 mL of the HCl and 20 mL of the NaOH. After complete stirring, the pH of the mixture will be

Equal volumes (5 mL)of vinegar from a freshly opened bottle are added to each of the following solutions. After complete mixing, which of the mixtures will have the highest pH?

What is the pH of a 1 millimolar NaOH solution?

Why does evaporation of water from a surface cause cooling of the surface?

Assume that acid rain has lowered the pH of a particular lake to pH 4.0. What is the hydroxyl ion concentration of this lake?

Introduction: Themes in the Study of Life

The Chemical Context of Life

Carbon and the Molecular Diversity of Life

The Structure and Function of Large Biological Molecules

A Tour of the Cell

Membrane Structure and Function

An Introduction to Metabolism

Cellular Respiration and Fermentation

Photosynthesis

Cell Communication

The Cell Cycle

Meiosis and Sexual Life Cycles

Mendel and the Gene Idea

The Chromosomal Basis of Inheritance

The Molecular Basis of Inheritance

From Gene to Protein

Regulation of Gene Expression

Viruses

Biotechnology

Genomes and Their Evolution

Descent with Modification: A Darwinian View of Life

The Evolution of Populations

The Origin of Species

The History of Life on Earth

Phylogeny and the Tree of Life

Bacteria and Archaea

Protists

Plant Diversity I: How Plants Colonized Land

Plant Diversity II: The Evolution of Seed Plants

Fungi

An Overview of Animal Diversity

An Introduction to Invertebrates

The Origin and Evolution of Vertebrates

Plant Structure, Growth, and Development

Resource Acquisition and Transport in Vascular Plants

Soil and Plant Nutrition

Angiosperm Reproduction and Biotechnology

Plant Responses to Internal and External Signals

Basic Principles of Animal Form and Function

Animal Nutrition

Circulation and Gas Exchange

The Immune System

Osmoregulation and Excretion

Hormones and the Endocrine System

Animal Reproduction

Animal Development

Neurons, Synapses, and Signaling

Nervous Systems

Sensory and Motor Mechanisms

Animal Behavior

An Introduction to Ecology and the Biosphere

Population Ecology

Community Ecology

Ecosystems and Restoration Ecology

Conservation Biology and Global Change

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