Deck 3: Alkanes and Cycloalkanes

Question 1

Which of the following molecules are alkanes?

A) I and II
B) II
C) I and III
D) I and IV

Answer 1

II

Question 2

How many primary carbons are in THC (tetrahydrocannabinol, the main psychoactive substance found in the Cannabis plant)?

A) 2
B) 3
C) 4
D) 5

Answer 2

4

Question 3

Which of the following sets are pairs of constitutional isomers?

A) I
B) II
C) III
D) II and IV

Answer 3

III

Question 4

Which is the IUPAC name for the following alkane?

A) 2-ethyl-3-methylpentane
B) 3,4-dimethylhexane
C) 2,3-diethylbutane
D) 3-methyl-4-ethylpentane

Question 5

Which is the IUPAC name for the following cycloalkane?

A) cis-1-ethyl-2-methylcyclohexane
B) trans-1-ethyl-2-methylcyclohexane
C) cis-1-methyl-2-ethylcyclohexane
D) trans-1-methyl-2-ethylcyclohexane

Question 6

Which of the following molecules are constitutional isomers?

A) I and IV
B) II and III
C) I , II, and IV
D) I, II, and III

Question 7

How many primary carbons are there in the following alkane?

A) 1
B) 2
C) 4
D) 6

Question 8

Which of the following are constitutional isomers of trans-1,2-dimethylcyclopentane?

I II III IV V

A) I, III, IV
B) II, IV, V
C) II, III, V
D) III, IV, V

Question 9

Which is the structure for trans-1-ethyl-3-isopropylcyclohexane?

A) I
B) II
C) III
D) IV

Question 10

Which conformation of pentane is most stable?

A) I
B) II
C) III
D) IV

Question 11

Which of the molecules are constitutional isomers?

A) I and II
B) I, II and III
C) I, IV, and V
D) I, II and IV

Question 12

Which of the following are constitutional isomers of 4-isopropyloctane?
I. 3-ethyl-2,4,5-trimethyloctane
II. isobutylcyclohexane
III. 4-ethyl-2,2-dimethylheptane
IV. 4-ethyl-2-methyloctane

A) I, IV
B) II, III
C) I, II
D) III, IV

Question 13

Which of the following molecules are constitutional isomers?

A) I and II
B) I, II, and III
C) I, III, and IV
D) II and III

Question 14

Which is the IUPAC name for the following cycloalkane?

A) 2,4-dimethyl-1-ethylcyclopentane
B) 1,3-dimethyl-5-ethylcyclopentane
C) 1-ethyl-2,4-dimethylcyclopentane
D) 1-ethyl-3,5-dimethylcyclopentane

Question 15

How many primary carbons are in cholesterol?

A) 2
B) 3
C) 4
D) 5

Question 16

Which of the following belong in the group of constitutional isomers for C₃H₆O₂?

A) II, III
B) II, IV, V
C) I, II, V
D) I, V

Question 17

Which of the following molecules are constitutional isomers?

A) I and II
B) II and IV
C) II and III
D) IV and V

Question 18

How many secondary hydrogens are there in the following alkane?

A) 1
B) 2
C) 4
D) 9

Question 19

Which of the following properties are not identical for constitutional isomers?
I. molecular formula
II. molecular weight
III. order of attachment of atoms
IV. physical properties

A) I, IV
B) II, III
C) I, II
D) III, IV

Question 20

Which pairs of molecules are constitutional isomers?

A) I, IV
B) I, II
C) II, III
D) III, IV

Question 21

In the most stable conformation of cis-1,3-dimethylcyclohexane, what positions do the methyl groups occupy?

A) axial, axial
B) equatorial, axial
C) equatorial, equatorial
D) axial, equatorial

Question 22

Draw a constitutional isomer of propanone (C₃H₆O).

Question 23

Which is a conformer of pentane?Which is a conformer of pentane

A)I
B)II
C)III
D)IV

Question 24

Which molecule has the most negative heat of combustion in kcal/mole?

A) methane
B) ethane
C) propane
D) butane

Question 25

In the most stable conformation of trans-1,4-dimethylcyclohexane, what positions do the methyl groups occupy?

A) axial, axial
B) equatorial, axial
C) equatorial, equatorial
D) axial, equatorial

Question 26

Which compound has the lowest boiling point?

A) I
B) II
C) III
D) IV

Question 27

Which cycloalkanes can exist as either cis- or trans-isomers?

A) I, V
B) I, II, V
C) II, III, V
D) II, III, IV

Question 28

What is the term for the process of forming ethene (an unsaturated hydrocarbon) from ethane (a saturated hydrocarbon)?

A) combustion
B) fractional distillation
C) thermal cracking
D) catalytic reformation

Question 29

In the most stable conformation of trans-1,2-dimethylcyclohexane, what positions do the methyl groups occupy?

A) axial, axial
B) equatorial, axial
C) axial, equatorial
D) equatorial, equatorial

Question 30

Which conformation of 2-methylbutane is the most stable?Hint: Build a molecular model!

A)I
B)II
C)III
D)IV

Question 31

Which are the stoichiometric coefficients that complete the following equation?

A) x = 9 ½, y = 6, z = 7
B) x = 18, y = 12, z = 14
C) x = 1, y = 1, z = 2
D) x = 6 , y = 6, z = 4

Question 32

Which compound has the highest boiling point?

A) I
B) II
C) III
D) IV

Question 33

Which is the IUPAC name for the following compound?

A) cis-5-isobutyl-2-isopropyl-1,3-dimethylcyclohexane
B) trans-5-isobutyl-2-isopropyl-1,3-dimethylcyclohexane
C) trans-5-isobutyl-2-isopropyl-1,3-dimethylcyclopentane
D) cis-1-isobutyl-2-isopropyl-4,5-dimethylcyclohexane

Question 34

What is the classification of the indicated carbon?

Question 35

Which conformer of pentane is the least stable?

A) I
B) II
C) III
D) IV

Question 36

Which conformation of 2-methylbutane is least stable?

A) I
B) II
C) III
D) IV

Question 37

Which structural formulas represent cis isomers of 1,2-dimethylcyclohexane?

A) I, IV
B) II, III
C) III, IV
D) I, II

Question 38

Which is the IUPAC name for the following compound?

A) cis-1-isobutyl-3-methylcyclohexane
B) trans-3-isobutyl-1-methylcyclohexane
C) trans-1-ethyl-3-methylcyclohexane
D) trans-1-isobutyl-3-methylcyclohexane

Question 39

Which of these diaxial conformations has the highest energy?

A) I
B) II
C) III
D) IV

Question 40

Which fraction of petroleum distills at the highest temperature?

A) gasoline
B) gases
C) fuel oil
D) kerosene

Question 41

The marked -CH₃ group in methyl acetate is a 1^o carbon.

Question 42

What is the classification of the indicated carbon?

Question 43

Alkanes all have lower densities than water.

Question 44

Propanal and propanol are constitutional isomers.

Question 45

Complete the following reaction by writing the stoichiometric coefficients.

Question 46

Pentane and cyclopentane are constitutional isomers.

Question 47

Write the name for the following molecule.

Question 48

Complete the Newman projection for the most stable conformation of 2-methylbutane. Use the appropriate Newman projection template.

Question 49

Complete the following reaction by writing the stoichiometric coefficients.

Question 50

The Newman projection below shows pentane in a gauche conformation.

Question 51

The Newman projection below shows 2,3-dimethylbutane in the most stable conformation.

Question 52

Complete the Newman projection for the least stable conformation of 2-methylbutane. Use the appropriate Newman projection template.

Question 53

Write the name for the following molecule.
___________________________________________

Question 54

The molecule shown has 12 primary (1°) hydrogens.

Question 55

The following structures represent the same molecule.

Question 56

The marked -CH₃ group in methyl acetate is a 1^o carbon .

Question 57

Complete the structure by drawing in the cis-1,3-dimethyl groups.

Question 58

The indicated carbon is a secondary (2°) carbon.

Question 59

The following structures represent the same molecule.

Question 60

Complete the structure by drawing in the trans-1,4-dimethyl groups.