chapters 3 & 4- water and carbon

3/9/13 Chapters 3 & 4

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Chapters 3 & 4

Due: 8:00am on Monday, February 11, 2013

Note: You will receive no credit for late submissions. To learn more, read your instructor's Grading Policy

Activity: The Polarity of Water

Click here to complete this activity.

Then answer the questions.

Part A

Each water molecule is joined to _____ other water molecules by ____ bonds.

ANSWER:

Correct

As can be seen in the illustration on page 1 of the activity titled "The Polarity of Water" a water molecule is joined to four other water moleculesby hydrogen bonds.

Part B

The unequal sharing of electrons within a water molecule makes the water molecule _____.

ANSWER:

Correct

The electrons spend more time with the oxygen of the water molecule than with the hydrogens of water. Thus, the oxygen has a net negativecharge and the hydrogens have a net positive charge.

Part C

The tendency of an atom to pull electrons toward itself is referred to as its _____.

ANSWER:

Biol 1002 - Spring 2013

Chapters 3 & 4 Resources

three ... ionic

two ... polar covalent

two ... hydrogen

four ... polar covalent

four ... hydrogen

have a low surface tension

polar

ionic

change easily from a liquid to gaseous form

hydrophobic

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3/9/13 Chapters 3 & 4


Correct

The question defines electronegativity.

Part D

In this molecule, what type of bond is found between the oxygen and hydrogens?

ANSWER:

Correct

While oxygen shares electrons with hydrogen, the electrons spend more time with the oxygen than with the hydrogens.

Part E

Which of these bonds is weakest?

ANSWER:

covalency

ionic potential

polarity

electronegativity

tonicity

ionic

polar covalent

hydrophilic

hydrophobic

nonpolar covalent

3/9/13 Chapters 3 & 4


Correct

Hydrogen Bonds are weaker than covalent bonds because they do not involve sharing of electrons, and they are weaker than ionic bonds becausethey involve the attraction of partial (not full) opposite charges.

Part F

Why isn't this insect drowning?

ANSWER:

Correct

The high surface tension of water allows the insect to remain on the surface.

Chapter 3 Pre-Test Question 1

Part A

Water molecules have a polarity, which allows them to be electrically attracted to other water molecules and other polar molecules by weak chemicalbonds known as _____.

The insect is very light.

It is difficult to change the temperature of water.

The insect is flying just above the water surface.

Surface tension.

The insect is swimming.

3/9/13 Chapters 3 & 4


Hint 1.

Consider the nature of the bonds that hold together the atoms of a water molecule. What higher level of organization does that arrangement leadto?

ANSWER:

Correct

The polarity of a water molecule allows the oxygen of one water molecule to bond weakly to the hydrogen of another water molecule.

Chapter 3 Question 1

Part A

In a single molecule of water, two hydrogen atoms are bonded to a single oxygen atom by

ANSWER:

Correct


Part A

The slight negative charge at one end of one water molecule is attracted to the slight positive charge of another water molecule. What is this attractioncalled?

ANSWER:

Correct


polar covalent bonds

Van der Waals interactions

hydrogen bonds

ionic bonds

nonpolar covalent bonds

ionic bonds.

hydrogen bonds.

polar covalent bonds.

van der Waals interactions.

nonpolar covalent bonds.

a covalent bond

a van der Waals interaction

a hydrophilic bond

a hydrogen bond

an ionic bond

3/9/13 Chapters 3 & 4


Part A

The partial negative charge in a molecule of water occurs because

ANSWER:

Correct

Hydrogen Bonding and Water

Water molecules (H2O) can form hydrogen bonds because of their molecular structure. Water exhibits many important properties because of hydrogenbonding.

Part A - Hydrogen bonding

Label the following diagram of water molecules, indicating the location of bonds and the partial charges on the atoms.

Drag the labels to their appropriate locations on the diagram of the water molecules below. Labels can be used once, more than once,or not at all.

Hint 1. Electronegativity and polar covalent bonds

In covalent bonds, the electrons are not always shared equally between the atoms. Some atoms hold electrons more tightly than others.Electronegativity is a measure of an atom’s attraction for electrons shared in a covalent bond. Atoms that have a high electronegativity holdelectrons more tightly than atoms that have a low electronegativity.A covalent bond in which electrons are shared unequally is called a polar covalent bond. The unequal sharing of electrons in a polar covalentbond results in partial charges on the atoms involved. The more electronegative atom will have a partial negative charge ( ) because shared

electrons spend more time around the nucleus of that atom. The less electronegative atom will have a partial positive charge ( ) because

shared electrons spend less time around the nucleus of that atom.

A polar molecule, such as water, is a molecule with opposite charges on its different ends due to the unequal sharing of electrons.

Hint 2. Can you match the terms about bonding to their definitions?

Drag the terms on the left to the appropriate blanks on the right to complete the sentences.

ANSWER:

the oxygen atom has two pairs of electrons in its valence shell that are not neutralized by hydrogen atoms.

the oxygen atom forms hybrid orbitals that distribute electrons unequally around the oxygen nucleus.

one of the hydrogen atoms donates an electron to the oxygen atom.

the oxygen atom acquires an additional electron.

the electrons shared between the oxygen and hydrogen atoms spend more time around the oxygen atom nucleus than around the hydrogenatom nucleus.

3/9/13 Chapters 3 & 4


Hint 3. Which statements about hydrogen bonding are true?

Which statements about hydrogen bonding in water are true?

Select all that apply.

ANSWER:

ANSWER:

The oxygen atom of a water molecule has a partial positive charge.

The hydrogen atom of one water molecule is attracted to the oxygen atom of a different water molecule.

The oxygen atom of a water molecule is more electronegative than a hydrogen atom.

The hydrogen atoms of a water molecule have a partial positive charge.

The hydrogen atom of a water molecule is attracted to the oxygen atom of the same water molecule.

The hydrogen atoms of a water molecule have a partial negative charge.

The oxygen atom of a water molecule has a partial negative charge.

3/9/13 Chapters 3 & 4


Correct

The image on the left shows the unequal sharing of electrons in a water molecule. Notice that the electrons are pulled toward the oxygen atom,which is more electronegative than a hydrogen atom, resulting in a partial negative charge ( ) on the oxygen atom and a partial positive charge (

) on each hydrogen atom.

The image on the right shows hydrogen bonding between two water molecules: the partially negative oxygen atom of one water molecule isattracted to the partially positive hydrogen atom of another water molecule. Hydrogen bonds are much weaker than covalent bonds. In liquid water,hydrogen bonds last only a fraction of a second, breaking and re-forming with great frequency. In a given instant, one water molecule can behydrogen bonded to up to four other water molecules.

Part B - Properties of water

Classify each statement as an example of adhesion, cohesion, or surface tension.

Drag each statement to the appropriate bin.

Hint 1. Can you match properties of water to their definitions?

Drag the terms on the left to the appropriate blanks on the right to complete the sentences. Not all terms will be used.

ANSWER:

3/9/13 Chapters 3 & 4


Hint 2. The role of hydrogen bonding in adhesion, cohesion, and surface tension in water

Water exhibits adhesion, cohesion, and surface tension due to water molecules’ ability to form hydrogen bonds.

Adhesion is a result of hydrogen bonding between water molecules and another type of molecule.Cohesion and surface tension are a result of hydrogen bonding between water molecules.

Hint 3. Example of adhesion and cohesion in water

The image below shows an example of adhesion and cohesion in a glass of water. The water molecules are attracted to the side of the glass(adhesion) and to each other (cohesion).

ANSWER:

3/9/13 Chapters 3 & 4


Correct

Water exhibits several different properties due to its ability to form hydrogen bonds, including adhesion, cohesion, and surface tension. Anexample of adhesion is the hydrogen bonding between water and another type of molecule, such as the molecules composing the side of a waterglass or beaker.Cohesion, on the other hand, is the attraction between like molecules. Water forms drops on a table because the water molecules are morestrongly attracted to each other through hydrogen bonding than they are to the molecules composing the table’s surface. Both adhesion andcohesion enable plants to transport water from the roots to the leaves against the force of gravity.Surface tension is the resistance of the surface of a liquid to stretching or breaking. Water’s surface tension results from the hydrogen bondsformed between the water molecules at the surface and between those surface molecules and the ones below. Water’s high surface tension isevident when certain insects are able to walk on the water’s surface.

Part C - Specific heat of water

The table shown here lists the specific heat of several substances.

SubstanceSpecific heat

water 4.18

ethyl alcohol 2.44

benzene 1.80

sulfuric acid 1.40

Based on the information in the table, which of the following statements are true?

Select all that apply.

Hint 1. Definition of specific heat

The specific heat of a substance is defined as the amount of heat that must be absorbed or lost for 1 g of that substance to change itstemperature by 1 . Specific heat may be written in several different units including joules per gram of substance per degree Celsius ( )

or calories per gram of substance per degree Celsius ( ).

Hint 2. Hydrogen bonding and specific heat

Recall that temperature is a measure of the average kinetic energy (energy of motion) of a substance’s molecules. By heating a substance, youincrease the speed of its molecules, and thus its temperature.It takes more energy to raise the temperature of a substance that exhibits a high degree of hydrogen bonding among its molecules. The reasonfor this is that much of the heat added to the substance is used to break those hydrogen bonds before the molecules can begin moving faster.This explains why water has a relatively high specific heat. The more hydrogen bonds that have to be broken, the more heat that must be addedto raise the temperature. In summary, more hydrogen bonding means higher specific heat.

3/9/13 Chapters 3 & 4


Hint 3. What are characteristics of substances with high specific heat and low specific heat?

Compare the general characteristics of a substance with high specific heat and a substance with low specific heat.

Drag each phrase to the appropriate bin.

ANSWER:

ANSWER:

Correct

Water has a high specific heat relative to other substances due to the hydrogen bonding that occurs between water molecules. Water is veryresistant to temperature increases because the hydrogen bonds between the water molecules must be disrupted to raise the temperature of thewater. By the same token, water must lose a large amount of heat and form many additional hydrogen bonds for its temperature to decrease.Water’s high specific heat has some important consequences for life on Earth. For example, coastal areas generally have milder climates thaninland areas due to the oceans' high specific heat. Oceans are able to absorb a large amount of heat during the daytime and summer, keeping airtemperatures relatively cool. At night and during the winter, the oceans cool gradually, releasing heat and warming the air. Water's high specificheat also stabilizes ocean temperatures, resulting in a favorable environment for marine life.

Activity: Cohesion of Water

Ethyl alcohol likely exhibits more hydrogen bonding than water.

Water is less resistant to temperature change than ethyl alcohol.

More heat is required to raise the temperature of 1 g of benzene 1 than to raise the temperature of 1 g of water 1 .

Water has a high specific heat due to the hydrogen bonding between water molecules.

Benzene is more resistant to temperature change than sulfuric acid.

More heat is required to raise the temperature of 1 g of water 1 than to raise the temperature of 1 g of ethyl alcohol 1 .

Sulfuric acid is less resistant to temperature change than water.

3/9/13 Chapters 3 & 4




Part A

What process is illustrated by this animation?To view the animation, click here. Then click on the image to start the animation.

What process is illustrated by this animation?

ANSWER:

Correct

Water is moving up the tree as it evaporates from the leaf surface.


Part A

Which of the following takes place as an ice cube cools a drink?

ANSWER:

Correct

The pH Scale

pH expresses the molar concentration of hydronium ions in an aqueous solution on a logarithmic scale. (Note that it is common to use the hydrogen ion,

H+, to represent the hydronium ion, H3O+.)

evaporation

push

gravity

precipitation

antigravity

The specific heat of the water in the drink decreases.

Evaporation of the water in the drink increases.

A calorie of heat energy is transferred from the ice to the water of the drink.

Kinetic energy in the drink decreases.

Molecular collisions in the drink increase.




3/9/13 Chapters 3 & 4


As pH decreases, acidity increases. As pHincreases, acidity decreases.

Acidic solution: pH < 7Neutral solution: pH = 7Basic solution: pH > 7

Part A - Calculating pH

What is the pH of an aqueous solution with the hydronium ion concentration

[H3O+] = 2 x 10-14 M ?

Make sure that your answer has the correct number of significant figures. For help determining the correct number of significant figures,see Hint 3.

Hint 1. How to approach the problem

Recall that pH is the negative log of the hydronium ion concentration, which in this problem is 2 x 10-14 M.

Hint 2. How to use a calculator to calculate a logarithm

For most scientific calculators, you can calculate the pH of the given hydronium ion concentration as follows:

1. Type 2 E 14 into your calculator.2. Press the +/- button to change the sign of the exponent.3. Press the LOG button.4. Press the +/- button again to change the sign of the answer.

Note that some graphing calculators allow you to type - LOG 2 E -14 followed by the ENTER button.

Practice by calculating -log [1 x 10-2]. The correct answer is 2.

Hint 3. Significant figures for log calculations

When you calculate the pH from the concentration, the final step is to adjust significant figures. In a pH value, the number to the left of thedecimal point is an exact number derived from a power of ten. The precision of the calculation therefore depends only on the concentration

coefficient. If a solution has a [H3O+] of 2 x 10-14 M, the pH will be expressed with one digit to the right of the decimal point, the same numberof significant digits as the concentration coefficient (2), which is the number with the fewest significant digits.

Hint 4. What is the calculated pH of a solution?

To test yourself on the rules for determining pH, calculate the pH of a solution with [H3O+] = 6 x 10-12 M.

Make sure that your answer has the correct number of significant figures. For help determining the correct number of significantfigures, see Hint 3.

ANSWER:

12

11.22

11.2

-11.2

12.8

3/9/13 Chapters 3 & 4


ANSWER:

Correct

With a pH of 13.7, this is a strongly basic solution. Concentrated bases can be quite caustic. For example, concentrated aqueous sodiumhydroxide (known commonly as lye) reacts with the lipid molecules that make cellular membranes. This quickly destroys the integrity of themembranes and kills cells, causing burns that are just as dangerous as those caused by concentrated acid.

Part B - Determining hydronium ion concentrations

Carbonated cola is more acidic than coffee or even orange juice because cola contains phosphoric acid.

What is the molar concentration of [H3O+] in a cola that has a pH of 3.120? (For help with significant figures, see Hint 3.)


pH is the negative log of the hydronium ion concentration. So hydronium ion concentration is the antilog of the negative pH, expressed as 10-pH.

Hint 2. How to use a calculator to take an antilog

The inverse log (or antilog) function on your calculator may be labeled 10x . It may be its own key but is more likely to be the second function of

the LOG key (in which case you will see 10x written above the LOG key). To access second functions on your calculator, press the keylabeled 2nd, SHIFT, or INV, then press the key that has the desired function written above it.

Here are step-by-step instructions:

1. Type 3.120 into your calculator.2. Press the +/- button to change the sign.3. Press the 2nd button followed by the LOG button.

Note that some graphing calculators allow you to type 10̂ -3.120 followed by the ENTER button.

Practice by calculating 10-0.2. The correct answer is 0.63.

Hint 3. Significant figures for inverse log calculations

When you calculate inverse log, the precision of the calculation depends only on the numbers to the right of the decimal point of the numberyou entered. There are three digits to the right of the decimal point in -3.120, so the exponential number you derive will have three significantfigures in the coefficient.

Hint 4. What is the molar concentration of H3O+ in a solution with a known pH?

Test your ability to calculate inverse log by choosing the correct molar concentration of H3O+ in a solution with a pH of 4.892.

Express your answer using the correct number of significant figures. For help determining the correct number of significantfigures, see Hint 3.

ANSWER:

ANSWER:

13.7

1.28 x 10-5

-.689

689

-77983

77983

3/9/13 Chapters 3 & 4


Correct

The molar concentration of [H3O+] in a cola with a pH of 3.120 can be calculated this way:

Ingestion of large amounts of phosphoric acid found in cola can upset the body's regulation of bone metabolism and reduce the absorption ofcalcium from the diet. For this reason, people who are at risk of developing osteoporosis are often advised not to drink much cola.

Part C - The relationship between pH and acidity

Rank the following from most acidic to least acidic.

Rank these items from most acidic to least acidic. To rank items as equivalent, overlap them.


Notice that three of the choices give the pH value, whereas two of the choices give the H3O+ concentration. So the first step is to convert allitems to a pH value before trying to rank them.

Hint 2. What is the pH of a solution with [H3O+] = 10-6?

Determine the pH of a solution with [H3O+] = 1.0 x 10-6 M.

Express the pH numerically.

ANSWER:

Hint 3. What is the pH of a solution with [H3O+] = 10-2?

Determine the pH of a solution with [H3O+] = 1.0 x 10-2 M.

Express the pH numerically.

ANSWER:

Hint 4. How does pH relate to acidity?

Determine the relationship between pH and acidity.

ANSWER:

ANSWER:

7.58 × 10−4

7.59 × 10−4

7.6 × 10−4

3.120 × 10−3

0.494

1.318 × 103

pH = 6.00

pH = 2.00

In comparing solutions, the solution with the highest pH is the most

least acidic.

3/9/13 Chapters 3 & 4


Correct

The 10-6 M H3O+ solution has a pH of 6, and the 10-2 M H3O+ solution has a pH of 2. The solutions are ranked from most acidic (pH = 2) to mostbasic (pH = 14).

Activity: Acids, Bases, and pH



Part A

What is the arrow pointing to?

ANSWER:

electron

hydrogen ion

water molecule

hydronium ion

hydroxide ion

3/9/13 Chapters 3 & 4


Correct

The arrow is indicating a single proton, a hydrogen ion (H+).

Part B

What is the arrow pointing to?

ANSWER:

Correct

The arrow is indicating a hydroxide ion (OH-).

Part C

In a neutral solution the concentration of _____.

ANSWER:

Correct

This is the definition of a neutral solution.

Part D

How does the pH of the solution on the right compare with that of the solution on the left?

ANSWER:

water

hydroxide ion

proton

hydronium ion

hydrogen ion

hydrogen ions is less than the concentration of hydroxide ions

hydrogen ions is equal to the concentration of hydroxide ions

water molecules is less than the concentration of hydrogen ions

hydrogen ions is greater than the concentration of hydroxide ions

water molecules is less than the concentration of hydroxide ions

Both of these solutions are equally basic.

The solution on the right is neutral relative to the solution on the left.

Both of these solutions are equally acidic.

The solution on the right is basic relative to the solution on the left.

The solution on the right is acidic relative to the solution on the left.

3/9/13 Chapters 3 & 4


Correct

The solution on the right has a lower concentration of hydrogen ions relative to hydroxide ions than does the solution on the left.


Part A

A pH of 6 is how many times more acidic than a pH of 9?

Hint 1.

The pH scale is a logarithmic scale.

ANSWER:

Correct

A pH of 6 is 10 times more acidic than 7, which is 10 times more acidic than 8, which is 10 times more acidic than 9. 10 x 10 x 10 = 1,000.


Part A

Most organic compounds contain carbon and _____.

Hint 1.

Think about the chemical formulas for methane and glucose.

ANSWER:

Correct

In fact, some argue that carbon dioxide should not be considered an organic molecule because it does not contain hydrogen.

Activity: Diversity of Carbon-Based Molecules

3

30

100

300

1,000

phosphate

nitrogen

hydrogen

oxygen

sulfur

3/9/13 Chapters 3 & 4




Part A

How do these hydrocarbons differ?

ANSWER:

Correct

The hydrocarbon on the right is longer than the hydrocarbon on the left.

Part B


ANSWER:

Correct

The hydrocarbon on the right is branched.

Part C


ANSWER:

One of these hydrocarbons has a ring structure.

One of these hydrocarbons is longer than the other.

One of these hydrocarbons has a double bond.

One of these hydrocarbons is branched.

These hydrocarbons are identical.








3/9/13 Chapters 3 & 4


Correct

The hydrocarbon on the right has a double bond.

Part D


ANSWER:

Correct

The hydrocarbon on the right has a ring structure.

Part E

How many hydrogen atoms can be attached to carbon A?

ANSWER:

Correct

A carbon atom can form up to four covalent bonds.

Part F

How many hydrogen atoms can be attached to carbon B?

ANSWER:










The hydrocarbon on the left contains more carbon atoms than the hydrocarbon on the right.

4

0

1

2

3

3/9/13 Chapters 3 & 4


Correct

A carbon atom can form up to four covalent bonds.

Activity: Isomers



Part A

L-dopa is used to treat _____.

ANSWER:

Correct

People with Parkinson's disease lack dopamine.

Part B

What kind of effect does R-dopa have on Parkinson's disease?

ANSWER:

Correct

R-dopa has no effect on Parkinson's disease.

Part C

These molecules are _____.

3

1

2

4

0

Parkinson's disease

Alzheimer's disease

laryngitis

muscle sprains

Marfan's syndrome

At first it alleviates the symptoms but over the long term it makes the symptoms worse.

It alleviates the symptoms.

It makes the symptoms of Parkinson's disease worse.

None.

At first it makes the symptoms worse but over the long term it alleviates the symptoms.



3/9/13 Chapters 3 & 4


ANSWER:

Correct

The two molecules differ in the covalent bond relationships among their atoms.

Part D


ANSWER:

Correct

These molecules differ in how their atoms are arranged about a double bond.

Part E


ANSWER:

Correct

These molecules are mirror images.

Part F

Enantiomers are molecules that _____.

ANSWER:

structural isomers

enantiomers

thiols

geometric isomers

amines

ATP and ADP

structural isomers

enantiomers

geometric isomers

thiols

R-dopa and L-dopa

structural isomers

thiols

enantiomers

geometric isomers

3/9/13 Chapters 3 & 4


Correct

This is the definition of enantiomers.

Part G

Geometric isomers are molecules that _____.

ANSWER:

Correct

This is the definition of geometric isomers.

Part H

This pair of molecules are _____.

ANSWER:

Correct

These molecules have different molecular formulas.

Carbon Bonding and Functional Groups

Hydrocarbons are molecules consisting of only carbon atoms and hydrogen atoms. Hydrocarbons form the basis of many types of organic molecules.In addition to carbon atoms and hydrogen atoms, many organic molecules also have groups of atoms called functional groups. These functional groupsmay be substituted for one or more of the hydrogen atoms of a hydrocarbon. The functional groups present in an organic molecule determine the chemicalbehavior of that molecule.

Part A - Carbon bonding

Which molecules show an appropriate number of bonds around each carbon atom?

Select the three that apply.

Hint 1. Formation of bonds with carbon

contain an –OH group

differ in the arrangement of their molecules about a double bond

are isomers that differ in the covalent partnerships between their atoms

contain a carboxyl group

are mirror images

are isomers in which one of the molecules contains an amino group and the other contains a phosphate group

differ in their molecular formulas

differ in the arrangement of their atoms about a double bond

are mirror images

are isomers that differ in the covalent partnerships between their atoms

enantiomers

structural isomers

identical

not isomers

geometric isomers

3/9/13 Chapters 3 & 4


A carbon atom has a total of six electrons. Four of a carbon atom's six electrons are located in the outermost shell (valence shell).

Since the valence shell of a carbon atom can hold a total of eight electrons, a carbon atom would need to gain or lose four electrons tocomplete its valence shell and form an ion. Instead, a carbon atom usually completes its valence shell by sharing its four electrons, formingcovalent bonds with other atoms.

Carbon atoms are tetravalent, meaning they form a total of four covalent bonds. A carbon atom may form different combinations of single,double, or even triple bonds as long as the total number of bonds around a carbon atom is four.

Hint 2. Single, double, and triple bonds

The table below shows how a single covalent bond, a double covalent bond, and a triple covalent bond between two general atoms, A and B,would be represented in a structural formula.

Type of bond Example

single bond

double bond

triple bond

A single bond indicates that two electrons are being shared between two atoms.A double bond indicates that four electrons are being shared between two atoms.A triple bond indicates that six electrons are being shared between two atoms.

Hint 3. Which combinations of single and double bonds are possible around a carbon atom?

Which combinations of single and double covalent bonds result in the appropriate number of bonds around a single carbon atom?

Select the three that apply.

ANSWER:

ANSWER:

3 single bonds and 1 double bond

2 single bonds and 1 double bond

4 single bonds

2 double bonds

3 single bonds

3/9/13 Chapters 3 & 4


Correct

Since carbon atoms are tetravalent (able to form four bonds), atoms may branch off a carbon atom in as many as four places. The ability of acarbon atom to form four different bonds allows carbon to form many different sizes and types of molecules. Carbon atoms may form chains,rings, or combinations of chains and rings. The tetravalence of carbon makes it particularly well-suited to forming the backbone of a huge diversityof organic molecules.

Part B - Identifying functional groups in a molecule

The molecule shown here contains four functional groups.

Highlight all the atoms of the four functional groups by clicking on them. When you click on each atom, it will change color. To deselectan atom, click on it again. Do not highlight any bonds.

Hint 1. Definition of functional group

A functional group is a specific configuration of atoms commonly attached to the carbon skeleton of an organic molecule. Functional groupsconfer specific chemical properties to the molecules of which they are a part. Atoms typically found in functional groups include oxygen,nitrogen, sulfur, and phosphorus.

Hint 2. Chemical structures of functional groups

The table below shows the formulas of six biologically important functional groups.

Functional group Formula

hydroxyl

carbonyl

carboxyl

amino

sulfhydryl

phosphate

Hint 3. Can you highlight the functional group of a molecule?

The molecule shown here contains a hydroxyl functional group.

Highlight the atoms of the hydroxyl group ( ) by clicking on them. When you click on each atom, it will change color. To

deselect an atom, click on it again. Do not highlight any bonds.

3/9/13 Chapters 3 & 4


ANSWER:

ANSWER:

Correct

A functional group is a group of atoms bonded together in a specific way that can replace a hydrogen atom in a hydrocarbon. The molecule shownhere contains four functional groups ( , , , and ) attached to a carbon chain that is six carbon atoms long.

Part C - Classifying molecules by their functional groups

Functional groups confer specific chemical properties to the molecules of which they are a part. In this activity, you will identify which compoundsexhibit certain chemical properties as well as examples of those six different compounds.

Drag one molecule (white label) and one chemical property (blue label) to each bin.

Hint 1. Organic compounds and their functional groups

The table below shows the formulas of six biologically important functional groups and the compounds in which they are found. In aldehydes,the carbonyl group is at the end of the carbon skeleton, whereas in ketones, it is within the carbon skeleton.

Compound Functional group Formula

alcohol hydroxyl

aldehyde or ketone carbonyl

carboxylic acid carboxyl

amine amino

3/9/13 Chapters 3 & 4


thiol sulfhydryl

organic phosphate phosphate

ANSWER:

Correct

Some biologically important functional groups include the hydroxyl group, the carbonyl group, the carboxyl group, the amino group, the sulfhydrylgroup, and the phosphate group. Phosphate groups, for example, are an important part of the structure of ATP (adenosine triphosphate), anenergy storage molecule in cells.


Part A

Which of the following hydrocarbons has a double bond in its carbon skeleton?

ANSWER:

Correct

Score Summary:

Your score on this assignment is 98.3%.You received 15.72 out of a possible total of 16 points.

chapters 3 & 4- water and carbon

Documents

water surface

hydrogens of water

single molecule of water

aeach water molecule

temperature of water

correctthe electrons

correctthe question

correcthydrogen bonds