Unit 7 – Organic Chemistry Fill in Key
'see explanation below'
1. Base your answer on the information below.
Many esters have distinctive odors, which lead to their widespread use as artificial flavorings and
fragrances. For example, methyl butanoate has an odor like pineapple and ethyl methanoate has an
odor like raspberry.
What is a chemical name for the alcohol that reacts with methanoic acid to produce the ester that
has an odor like raspberry? [1]
The ester ethyl methanoate is formed by the reaction of the alcohol ethanol with methanoic acid. [1
point]
'see explanation below'
2. Base your answer on the information below.
The incomplete equation shown represents an esterification reaction. The alcohol reactant is
represented by X.
On the structural formula on the answer sheet, or, if taken online, on a separate piece of paper,
circle the acid functional group, only. [1]
See Reference Table R. The functional group that is responsible for acidic properties is known as
the carboxyl group. It is shown in the accompanying diagram:
Note that either of these representations is acceptable for credit.
'see explanation below'
3. Base your answer on the information below.
The incomplete equation shown represents an esterification reaction. The alcohol reactant is
represented by X.
Write an IUPAC name for the reactant represented by its structural formula in this equation. [1]
The reactant whose structure is shown is an organic acid containing 2 carbon atoms. The name of
this compound is ethanoic (or acetic) acid.
'see explanation below'
4. Base your answer on the information below.
The incomplete equation shown represents an esterification reaction. The alcohol reactant is
represented by X.
In the space on the answer sheet, or, if taken online, on a separate piece of paper, draw the
structural formula for the alcohol represented by X. [1]
Esterification is the reaction between an acid and an alcohol. Therefore, compound X must be a 3carbon alcohol. Two acceptable versions of its structure are shown in the accompanying diagram:
'see explanation below'
5. Base your answer on the information below. The equation shown (see image) represents the
reaction between butanoic acid and an unidentified reactant, X.
Identify the type of organic reaction represented by the equation. [1]
Use Reference Table R to identify the organic product, which is an ester. The reaction is known as
esterification (or dehydration synthesis). [1 point]
'see explanation below'
6. Base your answer on the information below. The equation shown (see image) represents the
reaction between butanoic acid and an unidentified reactant, X.
In the space on the answer sheet or on a separate piece of paper, draw a structural formula for the
unidentified reactant, X, in the equation. [1]
In an esterification reaction, an organic acid (in this case, butanoic acid) reacts with an alcohol to
produce an ester and water. Since butanoic acid has four carbon atoms and the ester has six carbon
atoms, we can deduce that alcohol X has two carbon atoms. Its structural formula is:
'see explanation below'
7. Base your answer on the information below.
Many esters have distinctive odors, which lead to their widespread use as artificial flavorings and
fragrances. For example, methyl butanoate has an odor like pineapple and ethyl methanoate has an
odor like raspberry.
In the space provided or on a separate sheet of paper, draw a structural formula for the ester that has
an odor like pineapple. [1]
See Reference Tables P and R. The ester methyl butanoate is formed by the reaction of methanol (a
1-carbon alcohol) with butanoic acid (a 4-carbon organic acid). Three examples of acceptable
responses are shown in the accompanying image: [1 point]
'see explanation below'
8. Given the structural formula for butane:
On a separate sheet of paper, draw the structural formula of an isomer of butane. [1]
'see explanation below'
9. Given the ester: ethyl butanoate
a In the space provided (on a separate sheet of paper), draw the structural formula for this ester. [1]
b Determine the gram formula mass of this ester. [1]
'see explanation below'
10. On a separate piece of paper draw the structural formula for butanoic acid. [1]
Refer to the two possible diagrams of butanoic acid shown:
[1 point]
'see explanation below'
11. Base your answer on the information shown.
Ethene (common name ethylene) is a commercially important organic compound. Millions of tons
of ethene are produced by the chemical industry each year. Ethene is used in the manufacture of
synthetic fibers for carpeting and clothing, and it is widely used in making polyethylene. Lowdensity polyethylene can be stretched into a clear, thin film that is used for wrapping food products
and consumer goods. High-density polyethylene is molded into bottles for milk and other liquids.
Ethene can also be oxidized to produce ethylene glycol, which is used in antifreeze for
automobiles. The structural formula for ethylene glycol is:
At standard atmospheric pressure, the boiling point of ethylene glycol is 198°C, compared to ethene
that boils at -104°C.
Identify the type of organic reaction by which ethene (ehtylene) is made into polyethylene. [1]
Polyethylene is made from ethene by the process of polymerization. [1 point]
'see explanation below'
12. Base your answer on the information shown.
Ethene (common name ethylene) is a commercially important organic compound. Millions of tons
of ethene are produced by the chemical industry each year. Ethene is used in the manufacture of
synthetic fibers for carpeting and clothing, and it is widely used in making polyethylene. Lowdensity polyethylene can be stretched into a clear, thin film that is used for wrapping food products
and consumer goods. High-density polyethylene is molded into bottles for milk and other liquids.
Ethene can also be oxidized to produce ethylene glycol, which is used in antifreeze for
automobiles. The structural formula for ethylene glycol is:
At standard atmospheric pressure, the boiling point of ethylene glycol is 198°C, compared to ethene
that boils at -104°C.
According to the information in the reading passage, state two consumer products manufactured
from ethene. [1]
Consumer products manufactured from ethene include synthetic fibers, clothing, carpeting, food
wrap, bottles for containing liquids, and antifreeze.
Note that you need to list only two consumer products. [1 point]
'see explanation below'
13. Base your answer on the information shown.
Ethene (common name ethylene) is a commercially important organic compound. Millions of tons
of ethene are produced by the chemical industry each year. Ethene is used in the manufacture of
synthetic fibers for carpeting and clothing, and it is widely used in making polyethylene. Lowdensity polyethylene can be stretched into a clear, thin film that is used for wrapping food products
and consumer goods. High-density polyethylene is molded into bottles for milk and other liquids.
Ethene can also be oxidized to produce ethylene glycol, which is used in antifreeze for
automobiles. The structural formula for ethylene glycol is:
At standard atmospheric pressure, the boiling point of ethylene glycol is 198°C, compared to ethene
that boils at -104°C.
Explain, in terms of bonding, why ethene is an unsaturated hydrocarbon. [1]
The bond between the carbon atoms in ethene is a double bond. Hydrocarbons that contain double
or triple bonds are said to be unsaturated. Refer to the diagram of ethene (see image):
[1 point]
'see explanation below'
14. Base your answers to the question on the properties of propanone.
In the space provided or on a separate piece of paper, draw the structural formula for propanone.
Use Reference Tables P and R. The compound propanone has the prefix prop-, which means it has
three carbon atoms. It also has the suffix -one, which means that it is a ketone, that is, the carbonyl
group (C=O) is located on the second carbon atom. The structure is shown in the accompanying
diagram:
'see explanation below'
15. Base your answer on the accompanying equation, which represents an organic compound
reacting with bromine.
What is the IUPAC name for the organic compound that reacts with Br2? [1]
See Reference Tables P and Q. The organic compound is an alkene that contains 3 carbon atoms.
Its IUPAC name is propene. [1 point]
'see explanation below'
16. Base your answer on the accompanying equation, which represents an organic compound
reacting with bromine.
What type of organic reaction is represented by this equation? [1]
The organic reaction is called addition. (Note that the terms halogenation and bromination are also
acceptable for credit.) [1 point]
'see explanation below'
17. Base your answer on the accompanying equation, which represents an organic compound
reacting with bromine.
What is the gram-formula mass of the product in this reaction? [1]
Complete the accompanying table for C3H6Br2 and add the numbers in the last column: [1 point]
'see explanation below'
18. Base your answers on the information below.
During a bread-making process, glucose is converted to ethanol and carbon dioxide, causing the
bread dough to rise. Zymase, an enzyme produced by yeast, is a catalyst needed for this reaction.
a. Balance the accompanying equation in the space provided or on a separate piece of paper for the
reaction that causes bread dough to rise, using the smallest whole-number coefficients. [1]
b. In the space provided or on a separate piece of paper, draw a structural formula for the alcohol
formed in this reaction. [1]
c. State the effect of zymase on the activation energy for this reaction. [1]
a. The balanced equation, using smallest whole-number coefficients, is: (see solution image)
b. (see solution image)
c. Catalysts, such as zymase, increase the speed of a reaction by lowering the activation energy.
[1 point]
'see explanation below'
19. To which homologous series does CH3CH2CH2CH3 belong?
Use Reference Table Q. The compound represented by the formula CH3CH2CH2CH3 has no
carbon-to-carbon double or triple bonds, and its molecular formula (C4H10) corresponds to the
general formula CnH2n+2. This compound belongs to the alkane series of hydrocarbons.
'see explanation below'
20. Base your answer on the information below.
Given the balanced equation for an organic reaction between butane and chlorine that takes place at
300.oC and 101.3 kilopascals:
C4H10 + Cl2 --> C4H9Cl + HCl
Identify the type of organic reaction shown.
The organic reaction is known as substitution, in which a chlorine atom replaces one of the
hydrogen atoms in the alkane hydrocarbon. The replaced hydrogen atom combines with the
remaining chlorine atom to form HCl.
'see explanation below'
21. Base your answer on the information below.
Given the balanced equation for an organic reaction between butane and chlorine that takes place at
300.oC and 101.3 kilopascals:
C4H10 + Cl2 --> C4H9Cl + HCl
In the space on a separate piece of paper, draw a structural formula for the organic product.
Two possible examples of the organic product are shown in the accompanying diagram:
'see explanation below'
22. Base your answer on the information below.
A thiol is very similar to an alcohol, but a thiol has a sulfur atom instead of an oxygen atom in the
functional group. One of the compounds in a skunk's spray is 2-butene-1-thiol. The formula of this
compound is shown in the accompanying diagram.
Explain, in terms of composition, why this compound is a thiol.
Since a sulfur atom replaces an oxygen atom in a thiol, the functional group for a thiol must be SH. The compound in this question is a thiol because it contains the -SH functional group.
'see explanation below'
23. Base your answer on the information below.
Ozone gas, O3, can be used to kill adult insects in storage bins for grain without damaging the
grain. The ozone is produced from oxygen gas, O2, in portable ozone generators located near the
storage bins. The concentrations of ozone used are so low that they do not cause any environmental
damage. This use of ozone is safer and more environmentally friendly than a method that used
bromomethane, CH3Br. However, bromomethane was more effective than ozone because CH3Br
killed immature insects as well as adult insects.
Adapted From: The Sunday Gazette (Schenectady, NY) 3/9/03
Given the balanced equation for producing bromomethane:
Br2 + CH4 → CH3Br + HBr
Identify the type of organic reaction shown. [1]
The equation represents an organic substitution reaction, in which an atom of bromine replaces an
atom of hydrogen in CH4.
Note that bromination and halogenation also are acceptable answers.
[1 point]
'see explanation below'
24. Base your answer on the information below.
The hydrocarbon 2-methylpropane reacts with iodine as represented by the balanced equation
below. At standard pressure, the boiling point of 2-methylpropane is lower than the boiling point of
2-iodo-2-methylpropane.
To which class of organic compounds does this organic product belong? [1]
See Reference Table R. The organic product is classified as a halide (or halocarbon or alkyl halide).
[1 point]
'see explanation below'
25. Base your answer on the information below.
The hydrocarbon 2-methylpropane reacts with iodine as represented by the balanced equation
below. At standard pressure, the boiling point of 2-methylpropane is lower than the boiling point of
2-iodo-2-methylpropane.
Explain, in terms of bonding, why the hydrocarbon 2-methylpropane is saturated. [1]
The compound 2-methylpropane is saturated because there are no double or triple carbon-carbon
bonds present in the compound. [1 point]
'see explanation below'
26. Base your answer on the information below.
An unlit candle is secured to the bottom of a 200-milliliter glass beaker. Baking soda (sodium
hydrogen carbonate) is added around the base of the candle as shown below. The candle is lit and
dilute ethanoic acid is poured down the inside of the beaker. As the acid reacts with the baking
soda, bubbles of CO2 gas form. After a few seconds, the air in the beaker is replaced by 0.20 liter of
CO2 gas, causing the candle flame to go out. The density of CO2 gas is 1.8 grams per liter at room
temperature.
In the space on the answer sheet or on a separate piece of paper, draw a structural formula for the
acid that was poured into the beaker. [1]
See Reference Tables P and R. The condensed structural formula of ethanoic acid is CH3COOH.
The full structural formula of this acid is: [1 point]
'see explanation below'
27. Base your answer on the information below and accompanying diagram and on your knowledge
of chemistry.
Crude oil is a mixture of many hydrocarbons that have different numbers of carbon atoms. The use
of a fractionating tower allows the separation of this mixture based on the boiling points of the
hydrocarbons.
To begin the separation process, the crude oil is heated to about 400°C in a furnace, causing many
of the hydrocarbons of the crude oil to vaporize. The vaporized mixture is pumped into a
fractionating tower that is usually more than 30 meters tall. The temperature of the tower is highest
at the bottom. As vaporized samples of hydrocarbons travel up the tower, they cool and condense.
The liquid hydrocarbons are collected on trays and removed from the tower. The accompanying
diagram illustrates the fractional distillation of the crude oil and the temperature ranges in which
the different hydrocarbons condense.
How many hydrogen atoms are present in one molecule of octane?
See Reference Tables P and Q. Octane is an alkane with 8 carbon atoms. Since the general formula
for an alkane is CnH2n+2, the number of hydrogen atoms in octane will be:
2•8 + 2 = 18
'see explanation below'
28. Base your answer on the information below.
Diethyl ether is widely used as a solvent.
On a separate piece of paper, draw the structural formula for diethyl ether. [1]
'see explanation below'
29. Base your answer on the information below.
Diethyl ether is widely used as a solvent.
On a separate piece of paper, draw the structural formula for an alcohol that is an isomer of diethyl
ether. [1]
'see explanation below'
30. In the space to the right of the reactants and arrow provided (print this page), draw the structural
formula for the product of the reaction shown. [1]
The equation given in the answer booklet is shown:
This equation represents an addition reaction, in which a molecule of Br2 is "added" across the
double bond in the hydrocarbon (2-butene). One bromine atom is bonded to carbon atom 2, and one
bromine atom is bonded to carbon atom 3. As a result, the double bond between carbon atoms 2
and 3 is reduced to a single bond. Any of the structures shown below is acceptable for credit:
[1 point]
'see explanation below'
31. Base your answer on the information below.
Given the reaction between 1-butene and chlorine gas:
C4H8 + Cl2 --> C4H8Cl2
Which type of chemical reaction is represented by this equation?
1-butene contains a double bond. Hydrocarbons containing double and/or triple bonds will undergo
an addition reaction when combined with chlorine, bromine, or iodine.
Note that other acceptable responses include chlorination, halogenation, redox, and synthesis, but
addition is the preferred answer.
'see explanation below'
32. Base your answer on the information below.
Given the reaction between 1-butene and chlorine gas:
C4H8 + Cl2 --> C4H8Cl2
On a separate piece of paper, draw the structural formula of the product 1,2-dichlorobutane.
Two possibilities for the structural formula of 1,2-dichlorobutane are shown:
'see explanation below'
33. Base your answer on the information below and accompanying diagram and on your knowledge
of chemistry.
Crude oil is a mixture of many hydrocarbons that have different numbers of carbon atoms. The use
of a fractionating tower allows the separation of this mixture based on the boiling points of the
hydrocarbons.
To begin the separation process, the crude oil is heated to about 400°C in a furnace, causing many
of the hydrocarbons of the crude oil to vaporize. The vaporized mixture is pumped into a
fractionating tower that is usually more than 30 meters tall. The temperature of the tower is highest
at the bottom. As vaporized samples of hydrocarbons travel up the tower, they cool and condense.
The liquid hydrocarbons are collected on trays and removed from the tower. The accompanying
diagram illustrates the fractional distillation of the crude oil and the temperature ranges in which
the different hydrocarbons condense.
Write an IUPAC name of one saturated hydrocarbon that leaves the fractionating tower at less than
40°C.
Any alkane with 4 carbons or less will boil at a temperature less than 40°C. Any one of the
following is an acceptable answer: methane, ethane, propane, methylpropane, or butane.