week 11

Undecylic acid, shown below, is an organic molecule that is used as an antifungal agent, often to treat athlete's foot. Based on its structure, how many cis double bonds are present in undecylic acid?

0

How many different geometric isomers exist for a molecule designated as a propene? (Hint: consider both the placement of the double bond as well as cis and trans configurations possible.) Enter your answer as a numeric value.

1

Propane (C3H8) is a common hydrocarbon fuel for outdoor grills. Given the chemical equation for its combustion, how many moles of oxygen (O2) are required for the complete combustion of 2 moles of propane? C3H8+5O2→3CO2+4H2O

10

In a typical alkane, all of the bond angles are about

109.5

Carbon atoms in alkynes can contain which of the following bond angles? Select all that apply.

109.5∘ 120∘ 180∘

How many moles of oxygen gas react when 1 mole of 2,2-dimethylhexane undergoes complete combustion?Do not include units in your answer.

12.5

In an alkene, the bond angles surrounding the carbons participating in double bonds are:

120

Lycopene, shown below, is the red pigment in tomatoes. Based on its structure, how many double bonds are present in lycopene?

13

A linear alkane with 6 carbon atoms contains how many hydrogen atoms?

14 The general formula for linear alkanes is CnH2n+2, so an alkane with n=6 carbon atoms will have 2(n)+2=14 hydrogen atoms.

A double bond in an alkene takes the place of which of the following in the corresponding alkane?

2 hydrogens

Which will require the greatest number of moles of hydrogen to fully hydrogenate?

2-pentyne

What will be the product formed by hydration of propene? CH2=CH−CH3

2-propanol

Write the balanced equation for the complete combustion of 3-ethyl-2-methylpentane. Use the molecular formulas for all chemical species. Do not include state (phase) information for any chemical species. Be sure coefficients are the smallest possible whole numbers.

2C₈H₁₈ + 25O₂ → 16CO₂ + 18H₂O.

How many different geometric isomers exist for a molecule designated as a butene? (Hint: consider both the placement of the double bond as well as cis and trans configurations possible.)

3

How many total isomers are possible for a molecule of butene?

3

Which numbered carbon position is sp-hybridized? Select all that apply.

3 and 4

What is the name of this molecule? CH3−CH2−CH=CH−CH2−CH3

3-hexene

How many moles of oxygen gas react when a mole of ethane undergoes complete combustion?Do not include units in your answer.

3.5

How many moles of oxygen gas react when a mole of propane undergoes complete combustion?

5

Propane (C3H8) is a common hydrocarbon fuel for outdoor grills. Given the chemical equation for its combustion, how many moles of carbon dioxide (CO2) are produced in the complete combustion of 2 moles of propane?

6

How many moles of oxygen gas react when a mole of 2-methylbutane undergoes complete combustion?Do not include units in your answer.

8

How many structural isomers of n-heptane are there (including n-heptane itself)?

9

Which of the following gives the correct order of the groups, from least reactive to most reactive?

Alkanes, alkenes, alkynes

Which of the following is a hydrocarbon containing at least one carbon-carbon triple bond?

Alkyne

For 2,3-dimethylbutane, shown below, which of the following statements is false? The bond angles in the carbon skeleton are 109.5∘ All carbon atoms in the molecule are sp3 hybridized All single bonds in the molecule are sigma bonds The chemical formula for the molecule is C6H14 All single bonds in the molecule are pi bonds

All single bonds in the molecule are pi bonds

An alkene is described by which of the following?

An alkene is a molecule consisting of carbon and hydrogen containing at least one carbon-carbon double bond.

The melting point of two compounds are as follows: Benzaldehyde's melting point is −26∘C and barium chloride's is 962∘C. Identify which are likely to be organic and inorganic compounds from these values.

Benzaldehyde is more likely to be an organic compound because it has a low melting point. Barium chloride is likely to be inorganic because it has a high melting point.

Given the structure of acetylene, select the possible product for the hydrogenation of acetylene.

C2H6

An example of an alkene is:

CH2=CHCH=CH2

What is the condensed formula notation for 4-decyne?

CH3CH2CH2C≡CCH2CH2CH2CH2CH3

What will be the hydration product of 2-butene? CH3CH=CHCH3

CH3CHCH2CH3 | OH

Identify the hydration product of the given alkene. CH3|CH3CH2C=CH2

CH3−CH2−OH|C|CH3−CH3

dentify the correct product of complete hydrogenation of acetylene. HC≡CH

CH3−CH3

Which of the following is an alkyne? Select the correct answer below: CH3−CH2−CH(CH3)−CH3 CH3−C(CH3)2−C(CH3)2−CH3 CH2=C(CH3)−CH2−CH3 CH≡C−CH2−CH=CH3

CH≡C−CH2−CH=CH3

(Z)-9-tricosene, shown below, is a pheromone used by female houseflies to attract male flies. It is mass produced and used in household fly traps and fly paper. Based on its structure, what is the configuration of the double bond in (Z)-9-tricosene?

Cis

Alkenes have the formula

CnH2n

Branched chain alkanes have the formula:

CnH2n+2

Linear alkanes all have the formula

CnH2n+2

What type of alkane does not follow the CnH2n+2 formula?

Cyclic alkanes

Which of the following is a characteristic of alkanes? Select the correct answer below: Noncyclic alkanes have the molecular formula CnHn+1. The bond angles in some of their carbon chains are 180∘. Each of their carbon atoms is bonded to four other atoms. They have delocalized alternating carbon-carbon single and double bonds.

Each of their carbon atoms is bonded to four other atoms.

Organic chemistry is the chemistry of carbon-containing compounds. Organic molecules feature carbon atoms bonded to other carbon atoms as well as hydrogen atoms and a few other atoms (e.g., N, O, S, and P). Given this description, which of the compounds below is NOT an organic molecule?

Fe(NO3)2

Identify the correct product of complete hydrogenation of the given alkyne. H7C3−C≡C−C3H7

H7C3−CH2−CH2−C3H7

Ethylene (C2H4) is an important industrial chemical used in the production of plastics and helping fruits and vegetables to ripen. Given the chemical equation for the combustion reaction, which of the following statements is true? C2H4 (ethylene) +3O2→2CO2+2H2O Select the correct answer below: In a combustion reaction, all of the oxygen that reacts ends up in water. In a combustion reaction, all of the oxygen that reacts ends up in carbon dioxide. In a combustion reaction, all of the carbon that reacts ends up in carbon dioxide. In a combustion reaction, all of the water that reacts ends up in oxygen.

In a combustion reaction, all of the carbon that reacts ends up in carbon dioxide.

Determine whether iodide and formate are soluble in water based on whether or not each compound is organic.

Iodide is soluble because it is inorganic. Formate is not soluble because it is organic.

Rubber is a polymer made from repeating units of isoprene (also known as 2-methyl-1,3-butadiene), shown below. Based on its structure, which of the following statements is correct?

Isoprene has 0 cis double bonds and 0 trans double bonds

A compound has the molecular formula (C6H12O6). Explain why this compound is organic or inorganic.

It is organic because it is composed of carbon, hydrogen, and oxygen.

Classify the structure above as saturated or unsaturated, and give the reason.

It is unsaturated because it is aromatic, and it is not just composed of carbon-carbon single bonds.

Choose the options below that are not characteristics of alkanes. (select all that apply) Linear alkanes have the molecular formula CnH2n. They have delocalized alternating carbon-carbon single and double bonds. They interact through attractive van der Waals forces. They contain only single bonds.

Linear alkanes have the molecular formula CnH2n. They have delocalized alternating carbon-carbon single and double bonds.

Which of the following molecules does not exist? Select the correct answer below: Methene Ethene Propene Butene

Methene

Which of the following molecules is an alkene? H2C=O O=O H2C=NH None of the above

None of the above

Explain why hydrocarbons (organic molecules with just H and C) can have such a wide diversity of structures and properties despite being composed of only 2 elements. Choose the best explanation below.

Since carbon has 4 valence electrons, it can form 4 bonds, allowing for chains varying lengths and degrees of branching in structures formed from just C and H.

What is true about the bonding in alkenes? Select all that apply? Select all that apply: The carbon-carbon double bond in an alkene contains one sigma (σ) and one pi (π) bond. The carbon-carbon double bond can freely rotate. Geometric isomers result from a different orientation of atoms in space. Alkanes and alkenes are named identically, including using the "-ane" suffix.

The carbon-carbon double bond in an alkene contains one sigma (σ) and one pi (π) bond. Geometric isomers result from a different orientation of atoms in space.

For 1,3,5-hexatriene, shown below, which of the following statements is false? There are 3 pi bonds in the molecule There are 13 sigma bonds in the molecule The chemical formula for the molecule is C6H8 The molecule would be classified as an alkyne The bond angles in the carbon skeleton are 120∘

The molecule would be classified as an alkyne

Identify the correct statement about types of bonds that form in inorganic compounds. Select the correct answer below:

They are more often ionic bonds.

Which of the following is true of alkynes? The bond angles in their carbon chains do not exceed 120∘. They are unsaturated hydrocarbons. Each of their carbon atoms has sp hybrid orbitals. Each of their carbon atoms can rotate freely around its bonds.

They are unsaturated hydrocarbons.

Which of the following are true of alkenes? (Select all that apply) Select all that apply: They contain at least one sp2 hybrid orbital. Some of their carbon atoms are linked by one σ and two π bonds. They are unsaturated hydrocarbons. The bond angles in some of their carbon chains are 120∘.

They contain at least one sp2 hybrid orbital. They are unsaturated hydrocarbons. The bond angles in some of their carbon chains are 120∘.

Of the following, which are not characteristics of alkenes? (select all that apply) Select all that apply: They contain only carbon and hydrogen. They have only σ bonds. They contain at least one π bond. Each of their carbon atoms has sp3 hybrid orbitals.

They have only σ bonds. Each of their carbon atoms has sp3 hybrid orbitals.

Identify the inorganic compounds. a. iron oxide(Fe2O3) b. water (H2O) c. methane (CH4)

a and b

A hydrocarbon that contains single, double, and triple bonds between carbon atoms would be classified nominally as an:

aklyne

Ascorbic acid, shown below, is also known as vitamin C. It is important for wound healing and immune function. Given its structure, what structural feature is the most abundant in ascorbic acid?

alcohol (or hydroxyl) group

Geraniol, shown below, is an organic molecule that helps to give roses their distinctive fragrance. Based on its structure, what prominent functional group is found at the left end of the geraniol molecule?

alcohol (or hydroxyl) group

What will be the product formed by acid catalyzed hydration of alkenes?

alcohols

A fully saturated hydrocarbon is called an

alkane

An acyclic (not a ring) hydrocarbon with the molecular formula CnH2n must be which type of hydrocarbon?

alkene

If multiple different substituents are present in the same molecule, they will be listed in:

alphabetical order

Digitalis glycoside, shown below, is an organic molecule derived from foxglove plants that is used to treat heart rhythm abnormalities and improve blood flow in cardiac patients. Given the structure of digitalis glycoside, what structural feature is NOT present in the molecule?

amino

Curcumin, shown below, is a bright orange compound produced by plants such as turmeric. It is used as a food coloring agent and is thought to have beneficial effects on health. Given the structure of curcumin, what structural feature is NOT present in the molecule?

amino group

Luciferin, shown below, is produced by fireflies. When luciferin reacts with oxygen in the air, it decomposes and emits the firefly's familiar greenish-yellow light. Based on its structure, what two prominent functional groups are found at the ends of the luciferin molecule?

an alcohol (or hydroxyl) group on the left and a carboxylic acid group on the right

Which of the following may be a substituent on an alkane? Select the correct answer below: CH3 OH Br any of the above

any of the above

Organic compounds are generally non-polar in nature; however, some organic compounds are polar. What contributes to this polar nature? Select all that apply: the low density observed in organic compounds bonds between atoms with very different electronegativities weak, intermolecular London dispersion forces bonds between atoms with similar electronegativity

bonds between atoms with very different electronegativities

Write the molecular formula for toluene.

c(down)7 h(down)8

Which of the following is the formula for the simplest alkene (ethene)?

c2h4

Identify the correct molecular formula for the aromatic compound benzene.

c6h6

An alkene must contain one or more:

carbon-carbon double bonds

Shown below is acetylsalicylic acid, an organic molecule commonly known as aspirin. What functional group is prominent at the top-right portion of the molecule?

carboxylic acid group

Undecylic acid, shown below, is an organic molecule that is used as an antifungal agent, often to treat athlete's foot. Based on its structure, what prominent functional group is found at the end (left) of the undecylic acid molecule?

carboxylic acid group

Which of the following would be listed first when naming a molecule?

chloro

If two methyl groups on carbons connected by a double bond are on the same side of the double bond, which isomer is it?

cis

In the retina, the pigment retinol undergoes a change in configuration about one of its double bonds in response to absorbing a photon of light, as shown below. Based on the structures of retinol before and after the absorption of light, what configurational change occurs?

cis → trans configurational change about one of its double bonds

As the molecular mass of an alkane increases,

d. all of the above

When numbering the parent chain for a particular straight-chain alkane, on which we find one methyl group and one bromo group, which way will the molecule be numbered?

depends on their location on the molecule

What will be the hydration product of ethylene (systematic name ethene)? H|C|H=H|C|H

ethanol

Which of the following is an example of unsaturated hydrocarbon?

ethene

cinnemaldehyde, shown below, is an organic molecule that gives cinnamon its delightful aroma. Based on its structure, what prominent functional group is found at the end (top) of the cinnemaldehyde molecule?

ether

L-glutamine, shown below, is an amino acid that is thought to help maintain digestive health. Given the structure of L-glutamine, what structural feature is NOT present in the molecule?

ether group

Alkenes have identical properties to alkanes

false

Which n-alkane is an isomer of 3-methylpentane?

hexane

Which of the following alkanes is unbranched? Select the correct answer below: Methylpropane n-Butane Isopentane Neopentane

n-Butane

Which n-alkane is an isomer of 3-ethylpentane?

n-heptane

Which n-alkane is an isomer of 3-methylhexane?

n-heptane

Which n-alkane is an isomer of 2,3-dimethylbutane?

n-hexane

Which n-alkane is an isomer of 2-methylheptane?

n-octane

What is the product of complete hydrogenation of 2-pentyne, CH3CH2−C≡C−CH3?

n-pentane

SAMe (S-adenosyl methionine), shown below, is an important organic molecule used in reactions that occur in the liver. Given the structure of SAMe, what structural feature is NOT present in the molecule?

nitrogen-nitrogen single bonds

Which of the following could be an isomer of n-propane? Select the correct answer below: 1-propane 2-methylethane 2-methylpropane none of the above

none of the above

Which of the following is an example of a saturated hydrocarbon? Select the correct answer below: octane ethene benzene propyne

octane

The triple bond in an alkyne is comprised of:

one σ bond and two π bonds

Ethylene is a basic raw material used to make which of the following? (select all that apply) Select all that apply: carbohydrates petrochemicals plastics polymers

petrochemicals plastics polymers

Which of the following provides the most descriptive picture of carbon atom orientation an alkane?

skeletal structure

In an alkyne, the carbons participating in a triple bond will have what hybridization?

sp

In any ketone, the carbonyl carbon has what hybridization?

sp^2

Indicate the hybridization of orbitals of the central atom in NH+4.

sp^3

The molecules cis-2-butene and trans-2-butene are:

stereoisomers

An alkyl group attached to a carbon parent chain is called a

substituent

Structural isomers are molecules with:

the same molecular formula, but different connectivities

If two methyl groups on carbons connected by a double bond are on opposite sides of the double bond, which isomer is it?

trans

Alkenes must contain which of the following geometries in their structure?

trigonal planar

In IUPAC nomenclature, all alkynes will bear the suffix:

yne