Question 1

How many methylene groups are present in 2,4-dimethylhexane?
A) 0
B) 1
C) 2
D) 6
E) 8

Accepted Answer

A methylene group is a -CH2- unit. In 2,4-dimethylhexane, there are two 2-methyl and two 4-methyl groups attached to the six-carbon chain. There are two methylene groups that connect the 2-methyl group to the 4-methyl group, making a total of 2 methylene groups present in the molecule.

Question 2

If a hydrocarbon has no double or triple bonds, it is said to be ________.

Accepted Answer

saturated

Question 3

Which of the statements below accurately describe(s) alkanes?
A) Alkanes are hydrocarbons which contain only single bonds.
B) Alkanes belong to the class of unsaturated hydrocarbons.
C) Alkanes are the simplest and least reactive class of organic compounds.
D) both A and B
E) both A and C

Accepted Answer

Choice A is correct, as alkanes are hydrocarbons that contain only single bonds. Choice B is incorrect, as alkanes are actually saturated hydrocarbons, meaning they contain the maximum possible number of hydrogen atoms bonded to their carbons. Choice C is correct, as alkanes are typically unreactive under normal conditions and are considered the simplest class of organic compounds. Therefore, the best choice is E, as it correctly identifies the characteristics of alkanes as only containing single bonds (choice A) and being the least reactive class of organic compounds (choice C).

Question 4

A bicyclic alkane contains 12 carbon atoms. How many hydrogen atoms does it contain?
A) 20
B) 22
C) 24
D) 26
E) 28

Accepted Answer

The general formula for calculating the number of hydrogen atoms in a bicyclic alkane is CnH2n-2. For a bicyclic alkane with 12 carbon atoms (n=12), the number of hydrogen atoms is calculated as H = 2(12) - 2 = 24 - 2 = 22.

Question 5

Straight-chain alkanes are also called ________.

Accepted Answer

The answer of Straight-chain alkanes are also called ________....

Question 6

Provide an acceptable name for (CH₃CH₂CH₂)₃CH.

Accepted Answer

The answer of Provide an acceptable name for (CH₃CH₂CH₂)₃CH....

Question 7

Provide the name of the compound below.

Accepted Answer

The answer of Provide the name of the compound below....

Question 8

Name the haloalkane shown.

Accepted Answer

The answer of Name the haloalkane shown. ...

Question 9

Provide the name of the compound below.

Accepted Answer

The answer of Provide the name of the compound below....

Question 10

The structure below is a potent analgesic agent (pain reliever) (J. Med. Chem., 2009, 5685). How many secondary carbons are in this structure? 
A) 2
B) 4
C) 6
D) 12

Accepted Answer

The answer of The structure below is a potent analgesic...

Question 11

A student named the following molecule "4-isobutylheptane." Why is this incorrect? What is the correct name?

Accepted Answer

The answer of A student named the following molecule "4-isobutylheptane."...

Question 12

A series of compounds, like the n-alkanes, that differ only by the number of  
groups, is called a(n) ________ series.

Accepted Answer

The answer of A series of compounds, like the n-alkanes,...

Question 13

Draw an acceptable structure for 4-tert-butyloctane.

Accepted Answer

The answer of Draw an acceptable structure for 4-tert-butyloctane....

Question 14

Which of the following types of hydrocarbons is(are) saturated?
A) alkanes
B) alkenes
C) alkynes
D) aromatics
E) All of the above are saturated.

Accepted Answer

Alkanes are saturated hydrocarbons because they contain only single bonds between carbon atoms and are therefore fully saturated with hydrogen atoms. Alkenes and alkynes are unsaturated hydrocarbons because they contain at least one double or triple bond between carbon atoms, respectively. Aromatics, such as benzene, are also considered unsaturated due to the delocalized pi electron ring.

Question 15

Provide an acceptable name for the alkane shown below.

Accepted Answer

The answer of Provide an acceptable name for the alkane...

Question 16

How many secondary (2°) carbons are found in 5-ethyl-3,3,4-trimethylheptane?
A) 1
B) 4
C) 2
D) 3
E) 6

Accepted Answer

In 5-ethyl-3,3,4-trimethylheptane, a secondary carbon is bonded to two other carbon atoms. The structure has three secondary carbons.

Question 17

Draw an acceptable structure for 3-ethyl-3-methylhexane.

Accepted Answer

The answer of Draw an acceptable structure for 3-ethyl-3-methylhexane....

Question 18

If an acyclic alkane hydrocarbon contains n carbon atoms, how many hydrogen atoms must it also contain?
A) n
B) 2n
C) n + 2
D) 2n + 2
E) n - 2

Accepted Answer

An acyclic alkane hydrocarbon is a straight chain hydrocarbon with no cyclic structures. The general formula for an acyclic alkane hydrocarbon is CnH2n+2. Therefore, if it contains n carbon atoms, it must also contain 2n+2 hydrogen atoms.

Question 19

Provide an acceptable name for the alkane shown below. CH₃CH₂CH₂CH₂CH₂CH₃

Accepted Answer

The answer of Provide an acceptable name for the alkane...

Question 20

Triacontane is an unbranched alkane that contains 30 carbon atoms in each molecule. How many hydrogen atoms are present in each molecule of triacontane?
A) 30
B) 32
C) 58
D) 60
E) 62

Accepted Answer

The formula for calculating the number of hydrogen atoms in an unbranched alkane is CnH2n+2. For triacontane, n=30, so the number of hydrogen atoms is 2(30)+2=62.

Quiz 3: Structure and Stereochemistry of Alkanes

How many methylene groups are present in 2,4-dimethylhexane?

If a hydrocarbon has no double or triple bonds, it is said to be ________.

Which of the statements below accurately describe(s) alkanes?

A bicyclic alkane contains 12 carbon atoms. How many hydrogen atoms does it contain?

Straight-chain alkanes are also called ________.

Provide an acceptable name for (CH₃CH₂CH₂)₃CH.

Provide the name of the compound below.

Name the haloalkane shown.

Provide the name of the compound below.

The structure below is a potent analgesic agent (pain reliever) (J. Med. Chem., 2009, 5685) . How many secondary carbons are in this structure?

A student named the following molecule "4-isobutylheptane." Why is this incorrect? What is the correct name?

A series of compounds, like the n-alkanes, that differ only by the number of groups, is called a(n) ________ series.

Draw an acceptable structure for 4-tert-butyloctane.

Which of the following types of hydrocarbons is(are) saturated?

Provide an acceptable name for the alkane shown below.

How many secondary (2°) carbons are found in 5-ethyl-3,3,4-trimethylheptane?

Draw an acceptable structure for 3-ethyl-3-methylhexane.

If an acyclic alkane hydrocarbon contains n carbon atoms, how many hydrogen atoms must it also contain?

Provide an acceptable name for the alkane shown below. CH₃CH₂CH₂CH₂CH₂CH₃

Triacontane is an unbranched alkane that contains 30 carbon atoms in each molecule. How many hydrogen atoms are present in each molecule of triacontane?

Quiz 3: Structure and Stereochemistry of Alkanes

How many methylene groups are present in 2,4-dimethylhexane?

If a hydrocarbon has no double or triple bonds, it is said to be ________.

Which of the statements below accurately describe(s) alkanes?

A bicyclic alkane contains 12 carbon atoms. How many hydrogen atoms does it contain?

Straight-chain alkanes are also called ________.

Provide an acceptable name for (CH3CH2CH2)3CH.

Provide the name of the compound below.

Name the haloalkane shown.

Provide the name of the compound below.

The structure below is a potent analgesic agent (pain reliever) (J. Med. Chem., 2009, 5685) . How many secondary carbons are in this structure?

A student named the following molecule "4-isobutylheptane." Why is this incorrect? What is the correct name?

A series of compounds, like the n-alkanes, that differ only by the number of groups, is called a(n) ________ series.

Draw an acceptable structure for 4-tert-butyloctane.

Which of the following types of hydrocarbons is(are) saturated?

Provide an acceptable name for the alkane shown below.

How many secondary (2°) carbons are found in 5-ethyl-3,3,4-trimethylheptane?

Draw an acceptable structure for 3-ethyl-3-methylhexane.

If an acyclic alkane hydrocarbon contains n carbon atoms, how many hydrogen atoms must it also contain?

Provide an acceptable name for the alkane shown below. CH3CH2CH2CH2CH2CH3

Triacontane is an unbranched alkane that contains 30 carbon atoms in each molecule. How many hydrogen atoms are present in each molecule of triacontane?

Provide an acceptable name for (CH₃CH₂CH₂)₃CH.

Provide an acceptable name for the alkane shown below. CH₃CH₂CH₂CH₂CH₂CH₃