Question 1

Which of the following is the correct general molecular formula for a linear alkane with $$n$$ carbon atoms?

Accepted Answer

$$C_nH_{2n+2}$$

Question 2

What is the IUPAC name for the following structure?

A five-carbon chain with a methyl group attached to the third carbon.

Accepted Answer

3-methylpentane

Question 3

Which of the following statements about the physical properties of alkanes is TRUE?

Accepted Answer

Alkanes are generally insoluble in water but soluble in nonpolar solvents.

Question 4

Given the following substituents: methyl, ethyl, isopropyl, and tert-butyl, which one has the largest number of carbon atoms?

Accepted Answer

tert-butyl

Question 5

A molecule has the formula $$C_5H_{12}. $$Which of the following is NOT a possible isomer for this formula?

Accepted Answer

cyclopentane

Question 6

Which rule should be followed when numbering the main chain of an alkane with multiple substituents?

Accepted Answer

Number from the end closest to the first substituent encountered.

Question 7

What is the correct IUPAC name for the following molecule?

A six-carbon chain with methyl groups on carbons 2, 2, and 4.

Accepted Answer

2,2,4-trimethylhexane

Question 8

Which of the following best describes the hybridization and geometry of carbon atoms in alkanes?

Accepted Answer

sp3 hybridized, tetrahedral geometry

Question 9

Which of the following is the most stable conformation of ethane as shown in a Newman projection?

Accepted Answer

Staggered conformation

Question 10

Fractional distillation of crude oil separates alkanes based on which physical property?

Accepted Answer

Boiling point

Question 11

Which of the following is the correct IUPAC name for a molecule with a four-carbon chain and a methyl group attached to the second carbon?

Accepted Answer

2-methylbutane

Question 12

When naming a molecule with multiple substituents, which comes first in the name?

Accepted Answer

The substituent that comes first alphabetically

Question 13

Which of the following is a correct representation of a Newman projection for ethane in its lowest energy conformation?

Accepted Answer

Hydrogens on the front and back carbons are staggered at $$60^	ext{o}$$ angles

Question 14

Which of the following is NOT a correct rule for IUPAC alkane nomenclature?

Accepted Answer

Ignore the presence of multiple main chains and choose any chain.

Question 15

A molecule is named 3-ethyl-2-methylhexane. Which of the following is TRUE about its structure?

Accepted Answer

It has a six-carbon main chain with an ethyl group on carbon 3 and a methyl group on carbon 2.

Question 16

Which of the following is the correct condensed formula for n-butyl group?

Accepted Answer

$$CH_3CH_2CH_2CH_2-$$

Question 17

Which of the following statements about alkane conformations is correct?

Accepted Answer

Staggered conformations minimize electron repulsion between hydrogen atoms.

Question 18

Which of the following is the correct IUPAC name for a molecule with a seven-carbon chain and methyl groups on carbons 3, 5, and 6?

Accepted Answer

3,5,6-trimethylheptane

Question 19

Which of the following is a correct statement about the use of wedge and dash notation in organic chemistry?

Accepted Answer

Wedges represent bonds coming out of the plane of the paper, and dashes represent bonds going behind the plane.

Lecture 4 Part 1 - Properties and Nomenclature of Alkanes

Study Guide - Practice Questions