Copyright

Naming Alcohols Using IUPAC Nomenclature: Practice Problems

Instructor: Amanda Robb

Amanda holds a Masters in Science from Tufts Medical School in Cellular and Molecular Physiology. She has taught high school Biology and Physics for 8 years.

These practice problems will allow you to practice your skills in naming alcohols using the IUPAC nomenclature. First, we'll explain what alcohols are and review the nomenclature system, then we'll look at some examples of how to name alcohols.

What are Alcohols?

Many of us are already familiar with alcohols in adult beverages, or perhaps as a sanitizing fluid when we get a cut. But alcohols also have a wide variety of uses in the industrial sector. Alcohol is a good solvent for substances that aren't soluble in water and is used in many types of makeup and perfumes. Some types of alcohol can even be used as fuel for vehicles. Despite this wide range of uses, it's pretty easy to identify an alcohol. Alcohols are any organic molecule with a hydroxyl group, or -OH group, as the functional group.

There are three main types of alcohols: primary, secondary and tertiary. Primary alcohols have the hydroxyl group with a carbon that is only attached to one other carbon. Secondary alcohols have an OH group carbon that is attached to two other carbons, and as you might be thinking, tertiary alcohols have an OH group carbon attached to three other carbons. Today, we'll look at how to name each of these alcohols.

IUPAC Naming

The International Union of Pure and Applied Chemistry (IUPAC) dictates that all alcohols are named by identifying the longest alkane chain that contains the hydroxyl group and changing the end of the parent name to '-ol'.

The alcohol should be given the lowest substituent possible and the carbons numbered to accommodate this.

Before we get started, let's check out this table to review the IUPAC naming rules for alkanes:

Number of carbons Name
1 Methane
2 Ethane
3 Propane
4 Butane
5 Pentane
6 Hexane
7 Heptane
8 Octane
9 Nonane
10 Decane

Example Problem 1: Primary Alcohols

Name the alcohol below.

A primary alcohol
propanol

Step 1: Identify the Alkane

First, count how many carbons form the longest chain that contains the alcohol. In this example, there are three carbons, so the alkane base name is propane.

Step 2: Find the Lowest Substituent for the Alcohol

Next, we need to number the carbons so that the alcohol functional group gets the lowest number. Here, if we number from right to left, the alcohol group starts with 1.

Step 3: Name the Compound

Now we can name the compound by changing the alkane name to end in 'ol'. The name for this compound is 1-propanol, or just propanol.

Example Problem 2: Secondary Alcohols

Name the alcohol below.

A secondary alcohol
hexanol

Step 1: Identify the Alkane

The first step is to identify which alkane is the base by counting the number of carbons. In this diagram, each joint contains one carbon, so the total number of carbons here is six. A six carbon alkane is called hexane.

Step 2: Find the Lowest Substituent for the Alcohol

Now, we need to number the carbons so that the alcohol has the lowest possible substituent number. Here, if we count from right to left, the alcohol is branched from carbon 2.

To unlock this lesson you must be a Study.com Member.
Create your account

Register to view this lesson

Are you a student or a teacher?

Unlock Your Education

See for yourself why 30 million people use Study.com

Become a Study.com member and start learning now.
Become a Member  Back
What teachers are saying about Study.com
Try it risk-free for 30 days

Earning College Credit

Did you know… We have over 200 college courses that prepare you to earn credit by exam that is accepted by over 1,500 colleges and universities. You can test out of the first two years of college and save thousands off your degree. Anyone can earn credit-by-exam regardless of age or education level.

To learn more, visit our Earning Credit Page

Transferring credit to the school of your choice

Not sure what college you want to attend yet? Study.com has thousands of articles about every imaginable degree, area of study and career path that can help you find the school that's right for you.

Create an account to start this course today
Try it risk-free for 30 days!
Create an account
Support