Question 1

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

Question 2

Chemical evolution refers to which of the following?

Accepted Answer

A) Large molecules tended to break apart because of the intense sunlight and heat from volcanoes. 
B) Water condensed to form the first oceans. 
C) Small molecules reacted to form larger,more complex molecules. 
D) Earth's crust solidified,even as massive bombardment from outer space continued. 
A) Large molecules tended to break apart because of the intense sunlight and heat from volcanoes. 
B) Water condensed to form the first oceans. 
C) Small molecules reacted to form larger,more complex molecules. 
D) Earth's crust solidified,even as massive bombardment from outer space continued.

Question 3

To act as an effective coolant in a car's radiator,a substance has to be a liquid at the temperatures found in your car's engine and have the capacity to absorb a great deal of heat.You have a reference book with tables listing the physical properties of many liquids.In choosing a coolant for your car,which table would you check first?

Accepted Answer

A) pH 
B) density at room temperature 
C) heat of vaporization 
D) specific heat 
A) pH 
B) density at room temperature 
C) heat of vaporization 
D) specific heat

Question 4

Why would the spontaneous formation of formaldehyde and hydrogen cyanide not take place on Earth today as much as on the prebiotic Earth?

Accepted Answer

A) Microorganisms break these down immediately. 
B) The sun has changed its output. 
C) Atmospheric conditions on Earth,such as the presence of oxygen,have changed. 
A) Microorganisms break these down immediately. 
B) The sun has changed its output. 
C) Atmospheric conditions on Earth,such as the presence of oxygen,have changed.

Question 5

An atom has six electrons in its valence shell.How many single covalent bonds would you expect it to form in most circumstances?

Accepted Answer

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

Question 6

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 7

Why is water such a good solvent?

Accepted Answer

A) Most polar and charged substances dissolve in it. 
B) It is highly polar. 
C) It can participate in hydrogen bonds. 
D) All of the above apply. 
A) Most polar and charged substances dissolve in it. 
B) It is highly polar. 
C) It can participate in hydrogen bonds. 
D) All of the above apply.

Question 8

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 9

Which of the following is a violation of the first law of thermodynamics?

Accepted Answer

A) The amount of energy stored in a plant's cell as sugars after undergoing photosynthesis is less than the amount of sunlight it absorbed. 
B) A hydrogen bomb can destroy a large city with only a few pounds of explosive material. 
C) All of the energy in the universe today was present when the Big Bang occurred. 
D) The universe will eventually die,and it will have no energy left in it. 
A) The amount of energy stored in a plant's cell as sugars after undergoing photosynthesis is less than the amount of sunlight it absorbed. 
B) A hydrogen bomb can destroy a large city with only a few pounds of explosive material. 
C) All of the energy in the universe today was present when the Big Bang occurred. 
D) The universe will eventually die,and it will have no energy left in it.

Question 10

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 and obtained energy from the sun. 
B) chemosynthetic and obtained energy from chemicals. 
C) herbivorous and obtained energy from plants. 
D) carnivorous and obtained energy from animals. 
A) photosynthetic and obtained energy from the sun. 
B) chemosynthetic and obtained energy from chemicals. 
C) herbivorous and obtained energy from plants. 
D) carnivorous and obtained energy from animals.

Question 11

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 12

Carbon is an important element for biology because

Accepted Answer

A) of the variety of carbon skeletons and functional groups that can be built on them. 
B) it has very high electronegativity and forms highly stable bonds. 
C) carbon is so rare,organisms conserve it highly. 
D) it has the ability to form six covalent bonds. 
A) of the variety of carbon skeletons and functional groups that can be built on them. 
B) it has very high electronegativity and forms highly stable bonds. 
C) carbon is so rare,organisms conserve it highly. 
D) it has the ability to form six covalent bonds.

Question 13

Many scientific probes sent to other parts of the solar system are looking for signs of something so far known to exist only on Earth,namely

Accepted Answer

A) carbon. 
B) gold. 
C) nitrogen. 
D) life. 
A) carbon. 
B) gold. 
C) nitrogen. 
D) life.

Question 14

When one of the atoms involved in a covalent bond has a much higher electronegativity than the other atom,what type of bond results?

Accepted Answer

A) a double bond 
B) a hydrogen bond 
C) a nonpolar covalent bond 
D) a polar covalent bond 
A) a double bond 
B) a hydrogen bond 
C) a nonpolar covalent bond 
D) a polar covalent bond

Question 15

You need to write down information about a molecule that gives the most accurate picture of the relative sizes of the atoms involved and their relationship in space.Which representation would work best?

Accepted Answer

A) molecular formula 
B) structural formula 
C) ball-and-stick model 
D) space-filling model 
A) molecular formula 
B) structural formula 
C) ball-and-stick model 
D) space-filling model

Question 16

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.

Question 17

Which statement best summarizes the essence of chemical evolution?

Accepted Answer

A) Energy in the form of sunlight or heat was transformed into chemical energy. 
B) Instead of being radiated back to space,energy in the form of sunlight or heat was retained in the oceans and atmosphere because of water's high specific heat. 
C) Entropy increased. 
D) An increasing number of exothermic reactions occurred. 
A) Energy in the form of sunlight or heat was transformed into chemical energy. 
B) Instead of being radiated back to space,energy in the form of sunlight or heat was retained in the oceans and atmosphere because of water's high specific heat. 
C) Entropy increased. 
D) An increasing number of exothermic reactions occurred.

Question 18

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 19

The ability to sweat or pant is considered an adaptation.Why?

Accepted Answer

A) It allows a body to release excess water. 
B) It allows a body to absorb heat,due to water's high specific heat. 
C) It cools a body off,due to water's high heat of vaporization. 
D) It is an important signal to others that an individual is too hot. 
A) It allows a body to release excess water. 
B) It allows a body to absorb heat,due to water's high specific heat. 
C) It cools a body off,due to water's high heat of vaporization. 
D) It is an important signal to others that an individual is too hot.

Question 20

You need to write down information about a molecule,but need to indicate only which atoms it contains and how many of each.Which representation would work best?

Accepted Answer

A) molecular formula 
B) structural formula 
C) ball-and-stick model 
D) space-filling model 
A) molecular formula 
B) structural formula 
C) ball-and-stick model 
D) space-filling model

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

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

Chemical evolution refers to which of the following?

Why would the spontaneous formation of formaldehyde and hydrogen cyanide not take place on Earth today as much as on the prebiotic Earth?

An atom has six electrons in its valence shell.How many single covalent bonds would you expect it to form in most circumstances?

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?

Why is water such a good solvent?

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?

Which of the following is a violation of the first law of thermodynamics?

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

Why is carbon so important in biology?

Carbon is an important element for biology because

Many scientific probes sent to other parts of the solar system are looking for signs of something so far known to exist only on Earth,namely

When one of the atoms involved in a covalent bond has a much higher electronegativity than the other atom,what type of bond results?

You need to write down information about a molecule that gives the most accurate picture of the relative sizes of the atoms involved and their relationship in space.Which representation would work best?

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

Which statement best summarizes the essence of chemical evolution?

How many electrons are involved in a single covalent bond?

The ability to sweat or pant is considered an adaptation.Why?

You need to write down information about a molecule,but need to indicate only which atoms it contains and how many of each.Which representation would work best?

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, RNA Processing, 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 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

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

Behavioural Ecology

Population Ecology

Community Ecology

Ecosystems

Biodiversity and Conservation Biology

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