Question 1

Measurements show that the pH of a particular lake is 4.0. What is the hydrogen ion concentration of the lake?

Accepted Answer

A)  4.0 M 
B)  10⁻¹⁰ M 
C)  10⁻⁴ M 
D)  10⁴ M 
E)  4% 
A)  4.0 M 
B)  10⁻¹⁰ M 
C)  10⁻⁴ M 
D)  10⁴ M 
E)  4%

Question 2

The molecular weight of water is 18 daltons. What is the molarity of 1 liter of pure water? (Hint: What is the mass of 1 liter of pure water?)

Accepted Answer

A)  55.6 M 
B)  18 M 
C)  37 M 
D)  0.66 M 
E)  1.0 M 
A)  55.6 M 
B)  18 M 
C)  37 M 
D)  0.66 M 
E)  1.0 M

Question 3

How many molecules of glycerol (C₃H₈O₃; molecular mass = 92)would be present in 1 L of a 1 M glycerol solution?

Accepted Answer

A)  1 × 10⁶ 
B)  14 × 6.02 × 10²³ 
C)  92 × 6.02 × 10²³ 
D)  6.02 × 10²⁶ 
E)  6.02 × 10²³ 
A)  1 × 10⁶ 
B)  14 × 6.02 × 10²³ 
C)  92 × 6.02 × 10²³ 
D)  6.02 × 10²⁶ 
E)  6.02 × 10²³

Question 4

Liquid water's high specific heat is mainly a consequence of the

Accepted Answer

A)  small size of the water molecules. 
B)  high specific heat of oxygen and hydrogen atoms. 
C)  absorption and release of heat when hydrogen bonds break and form. 
D)  fact that water is a poor heat conductor. 
E)  higher density of liquid water than solid water (ice). 
A)  small size of the water molecules. 
B)  high specific heat of oxygen and hydrogen atoms. 
C)  absorption and release of heat when hydrogen bonds break and form. 
D)  fact that water is a poor heat conductor. 
E)  higher density of liquid water than solid water (ice).

Question 5

Many mammals control their body temperature by sweating. Which property of water is most directly responsible for the ability of sweat to lower body temperature?

Accepted Answer

A)  water's change in density when it condenses 
B)  water's ability to dissolve molecules in the air 
C)  the release of heat by the formation of hydrogen bonds 
D)  the absorption of heat by the breaking of hydrogen bonds 
E)  water's high surface tension 
A)  water's change in density when it condenses 
B)  water's ability to dissolve molecules in the air 
C)  the release of heat by the formation of hydrogen bonds 
D)  the absorption of heat by the breaking of hydrogen bonds 
E)  water's high surface tension

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 dissociates into a bicarbonate ion (HCO₃⁻)and a hydrogen ion (H⁺). Thus,
H₂CO₃ ↔ HCO₃⁻ + H⁺
If the pH of the blood drops, one would expect

Accepted Answer

A)  a decrease in the concentration of H₂CO₃ and an increase in the concentration of HCO₃⁻. 
B)  the concentration of hydroxide ion (OH⁻) to increase. 
C)  the concentration of bicarbonate ion (HCO₃⁻) to increase. 
D)  the HCO₃⁻ to act as a base and remove excess H⁺ with the formation of H₂CO₃. 
E)  the HCO₃⁻ to act as an acid and remove excess H⁺ with the formation of H₂CO₃. 
A)  a decrease in the concentration of H₂CO₃ and an increase in the concentration of HCO₃⁻. 
B)  the concentration of hydroxide ion (OH⁻) to increase. 
C)  the concentration of bicarbonate ion (HCO₃⁻) to increase. 
D)  the HCO₃⁻ to act as a base and remove excess H⁺ with the formation of H₂CO₃. 
E)  the HCO₃⁻ to act as an acid and remove excess H⁺ with the formation of H₂CO₃.

Question 7

If the pH of a solution is increased from pH 5 to pH 7, it means that the

Accepted Answer

A)  concentration of H⁺ is twice (2X) what it was at pH 5. 
B)  concentration of H⁺ is one-half (1/2) what it was at pH 5. 
C)  concentration of OH⁻ is 100 times greater than what it was at pH 5. 
D)  concentration of OH⁻ is one-hundredth (0.01X) what it was at pH 5. 
E)  concentration of H⁺ is 100 times greater and the concentration of OH⁻ is one-hundredth what they were at pH 5. 
A)  concentration of H⁺ is twice (2X) what it was at pH 5. 
B)  concentration of H⁺ is one-half (1/2) what it was at pH 5. 
C)  concentration of OH⁻ is 100 times greater than what it was at pH 5. 
D)  concentration of OH⁻ is one-hundredth (0.01X) what it was at pH 5. 
E)  concentration of H⁺ is 100 times greater and the concentration of OH⁻ is one-hundredth what they were at pH 5.

Question 8

One mole (mol)of glucose (molecular mass = 180 daltons)is

Accepted Answer

A)  180 × 10²³ molecules of glucose. 
B)  1 kg of glucose dissolved in 1 L of solution. 
C)  the largest amount of glucose that can be dissolved in 1 L of solution. 
D)  180 kilograms of glucose. 
E)  both 180 grams of glucose and 6.02 × 10²³ molecules of glucose. 
A)  180 × 10²³ molecules of glucose. 
B)  1 kg of glucose dissolved in 1 L of solution. 
C)  the largest amount of glucose that can be dissolved in 1 L of solution. 
D)  180 kilograms of glucose. 
E)  both 180 grams of glucose and 6.02 × 10²³ molecules of glucose.

Question 9

One liter of a solution of pH 9 has how many more hydroxyl ions (OH⁻)than 1 L of a solution of pH 4?

Accepted Answer

A)  5 times more 
B)  32 times more 
C)  50,000 times more 
D)  10,000 times more 
E)  100,000 times more 
A)  5 times more 
B)  32 times more 
C)  50,000 times more 
D)  10,000 times more 
E)  100,000 times more

Question 10

A beaker contains 100 mL of NaOH solution at pH = 13. A technician carefully pours into the beaker 10 mL of HCl at pH = 1. Which of the following statements correctly describes the results of this mixing?

Accepted Answer

A)  The concentration of Na⁺ ion rises. 
B)  The concentration of Cl⁻ ion will be 0.1 M. 
C)  The concentration of undissociated H₂O molecules remains unchanged. 
D)  The pH of the beaker's contents will be neutral. 
E)  The pH of the beaker's contents falls. 
A)  The concentration of Na⁺ ion rises. 
B)  The concentration of Cl⁻ ion will be 0.1 M. 
C)  The concentration of undissociated H₂O molecules remains unchanged. 
D)  The pH of the beaker's contents will be neutral. 
E)  The pH of the beaker's contents falls.

Exam 3: Water and Life

Measurements show that the pH of a particular lake is 4.0. What is the hydrogen ion concentration of the lake?

The molecular weight of water is 18 daltons. What is the molarity of 1 liter of pure water? (Hint: What is the mass of 1 liter of pure water?)

How many molecules of glycerol (C₃H₈O₃; molecular mass = 92)would be present in 1 L of a 1 M glycerol solution?

Liquid water's high specific heat is mainly a consequence of the

Many mammals control their body temperature by sweating. Which property of water is most directly responsible for the ability of sweat to lower body temperature?

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

If the pH of a solution is increased from pH 5 to pH 7, it means that the

One mole (mol)of glucose (molecular mass = 180 daltons)is

One liter of a solution of pH 9 has how many more hydroxyl ions (OH⁻)than 1 L of a solution of pH 4?

A beaker contains 100 mL of NaOH solution at pH = 13. A technician carefully pours into the beaker 10 mL of HCl at pH = 1. Which of the following statements correctly describes the results of this mixing?

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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