Question 1

Which of the following is true of carbon?

Accepted Answer

A) It only forms polar molecules. 
B) It can form a maximum of three covalent bonds with other elements. 
C) It is highly electronegative. 
D) It can form polar and nonpolar bonds. 
A) It only forms polar molecules. 
B) It can form a maximum of three covalent bonds with other elements. 
C) It is highly electronegative. 
D) It can form polar and nonpolar bonds.

Question 2

Which of the following true statements can be attributed to water's high specific heat?

Accepted Answer

A) Oil and water do not mix well. 
B) Our body temperature can take a long time to passively change because it is composed mostly of water. 
C) Ice floats on water. 
D) Sugar dissolves in hot tea faster than in iced tea. 
A) Oil and water do not mix well. 
B) Our body temperature can take a long time to passively change because it is composed mostly of water. 
C) Ice floats on water. 
D) Sugar dissolves in hot tea faster than in iced tea.

Question 3

You've been asked to analyze a reaction that took place at 300 K.∆H was -150 and ∆S was +0.4.Is the reaction endothermic or exothermic?

Accepted Answer

A) endothermic 
B) exothermic 
C) You cannot tell unless you know the potential energy of the reactants and products. 
D) You cannot tell unless you know the amount of disorder in the reactants and products. 
A) endothermic 
B) exothermic 
C) You cannot tell unless you know the potential energy of the reactants and products. 
D) You cannot tell unless you know the amount of disorder in the reactants and products.

Question 4

The first chemicals that provided potential energy on Earth may have been formaldehyde and hydrogen cyanide.While these were produced by sunlight-driven reactions,they also occur around deep-sea vents.If the first organisms on Earth evolved around these vents,the first life on Earth was _____.

Accepted Answer

A) photosynthetic: obtained energy from the Sun 
B) chemosynthetic: obtained energy from chemicals 
C) herbivorous: obtained energy from plants 
D) carnivorous: obtained energy from animals 
A) photosynthetic: obtained energy from the Sun 
B) chemosynthetic: obtained energy from chemicals 
C) herbivorous: obtained energy from plants 
D) carnivorous: obtained energy from animals

Question 5

What does it mean to say a system has a ∆G equal to zero?

Accepted Answer

A) The system does not release or absorb heat. 
B) The system is perfectly ordered (no entropy). 
C) The total amount of potential energy in the system is zero. 
D) The system is at equilibrium. 
A) The system does not release or absorb heat. 
B) The system is perfectly ordered (no entropy). 
C) The total amount of potential energy in the system is zero. 
D) The system is at equilibrium.

Question 6

Which of the following tends to make chemical reactions spontaneous?

Accepted Answer

A) The reactants have lower potential energy than the products. 
B) The reactants are more ordered than the products. 
C) The temperature is low. 
D) The pressure is low. 
A) The reactants have lower potential energy than the products. 
B) The reactants are more ordered than the products. 
C) The temperature is low. 
D) The pressure is low.

Question 7

Why are some reactions exothermic?

Accepted Answer

A) The products have lower potential energy than the reactants. 
B) They are spontaneous. 
C) They are nonspontaneous. 
D) The products have higher entropy (are more disordered)than the reactants. 
A) The products have lower potential energy than the reactants. 
B) They are spontaneous. 
C) They are nonspontaneous. 
D) The products have higher entropy (are more disordered)than the reactants.

Question 8

Why is carbon so important in biology?

Accepted Answer

A) It is a common element on Earth. 
B) It has very little electronegativity,making it a good electron donor. 
C) It bonds to only a few other elements. 
D) It forms up to four covalent bonds. 
A) It is a common element on Earth. 
B) It has very little electronegativity,making it a good electron donor. 
C) It bonds to only a few other elements. 
D) It forms up to four covalent bonds.

Question 9

The structural formula for a certain molecule includes a group symbolized -O.The dash next to the oxygen atom means that a single bond exists to another atom,such as a carbon.Based on the valence of oxygen and the number of bonds it normally forms,what is the charge on the oxygen atom in this case?

Accepted Answer

A) +1 
B) -1 
C) +2 
D) -2 
A) +1 
B) -1 
C) +2 
D) -2

Question 10

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

Accepted Answer

A) ΔH is small,so melting still obeys the second law of thermodynamics. 
B) The Gibbs free-energy relationship 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) ΔH is small,so melting still obeys the second law of thermodynamics. 
B) The Gibbs free-energy relationship 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.

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

Which of the following is true of carbon?

Which of the following true statements can be attributed to water's high specific heat?

You've been asked to analyze a reaction that took place at 300 K.∆H was -150 and ∆S was +0.4.Is the reaction endothermic or exothermic?

The first chemicals that provided potential energy on Earth may have been formaldehyde and hydrogen cyanide.While these were produced by sunlight-driven reactions,they also occur around deep-sea vents.If the first organisms on Earth evolved around these vents,the first life on Earth was _____.

What does it mean to say a system has a ∆G equal to zero?

Which of the following tends to make chemical reactions spontaneous?

Why are some reactions exothermic?

Why is carbon so important in biology?

The structural formula for a certain molecule includes a group symbolized -O.The dash next to the oxygen atom means that a single bond exists to another atom,such as a carbon.Based on the valence of oxygen and the number of bonds it normally forms,what is the charge on the oxygen atom in this case?

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

Biology and the Tree of Life

Protein Structure and Function

Nucleic Acids and the Rna World

An Introduction to Carbohydrates

Lipids, membranes, and the First Cells

Inside the Cell

Cell-Cell Interactions

Cellular Respiration and Fermentation

Photosynthesis

The Cell Cycle

Meiosis

Mendel and the Gene

Dna and the Gene: Synthesis and Repair

How Genes Work

Transcription and Translation

Control of Gene Expression in Bacteria

Control of Gene Expression in Eukaryotes

Analyzing and Engineering Genes

Genomics

Principles of Development

An Introduction to Animal Development

An Introduction to Plant Development

Evolution by Natural Selection

Evolutionary Processes

Speciation

Phylogenies and the History of Life

Bacteria and Archaea

Protists

Green 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

Animal Form and Function

Water and Electrolyte Balance in Animals

Animal Nutrition

Gas Exchange and Circulation

Electrical Signals in Animals

Animal Sensory Systems and Movement

Chemical Signals in Animals

Animal Reproduction

The Immune System in Animals

An Introduction to Ecology

Behavioral Ecology

Population Ecology

Community Ecology

Ecosystems

Biodiversity and Conservation Biology

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