Login
Copyright

Heptane: Structure, Uses & Formula

An error occurred trying to load this video.

Try refreshing the page, or contact customer support.

Coming up next: Homogeneous Mixture: Definition & Examples

You're on a roll. Keep up the good work!

Take Quiz Watch Next Lesson
 Replay
Your next lesson will play in 10 seconds
  • 0:00 There Wouldn't Be An…
  • 0:45 Structure & Properties…
  • 1:38 How Heptane Is Used
  • 3:07 Sources Of Heptane
  • 3:38 Safety & Handling Of Heptane
  • 3:59 Lesson Summary
Add to Add to Add to

Want to watch this again later?

Log in or sign up to add this lesson to a Custom Course.

Login or Sign up

Timeline
Autoplay
Autoplay
Create an account to start this course today
Try it free for 5 days!
Create An Account

Recommended Lessons and Courses for You

Lesson Transcript
Instructor: Andrea Kropp

Andrea holds a master's degree in Chemistry and has taught General and Organic Chemistry, Biology and Physics at the college level.

Discover the structure, physical properties, sources, and uses of the saturated hydrocarbon heptane (C7H16). Learn about heptane's vital role in establishing the octane rating scale for gasoline.

There Wouldn't Be an Octane Rating Without Heptane!

If you own a car, you might be familiar with octane ratings. Every time you go to the pump, you have to choose between gasolines rated with numbers such as 87, 89 or 91 -- these are octane ratings. But wait, this lesson is supposed to be about heptane, right? Well, the most interesting fact about heptane is that it is used to define the zero point on the octane rating scale.

By definition, when the octane rating scale was created, 100% pure heptane was given a rating of 0. Before being made available for sale, all gasolines are measured against pure heptane to determine their octane rating. So what exactly is heptane and where does it come from?

Structure and Properties of Heptane

Heptane is the name for the straight-chained saturated hydrocarbon with 7 carbon atoms and 16 hydrogen atoms. The 7 carbon atoms are connected in one long chain with no branches. It is said to be fully saturated because it contains no double bonds between carbons. Hydrogens are attached such that each carbon makes 4 bonds to other atoms.

Heptane's molecular formula is C7H16, and its chemical structure can be drawn in many ways that are all equivalent to one another. Sometimes the name will be written 'n-heptane', where the n stands for normal and conveys that the seven carbon atoms are arranged in a straight line.

At room temperature, heptane is a colorless liquid with a gasoline-like odor. It readily gives off fumes, and both the liquid and the fumes are highly flammable.

How Heptane is Used

Pure heptane has two main uses. The first use is as the standard zero point for the octane rating scale for gasoline. As a driver, you may have noticed that higher octane fuel is more expensive because it is better for your engine. You can correctly conclude that a fuel rated zero octane would be terrible for your car. Indeed, pure heptane with its zero octane rating is a terrible fuel choice. The reason is that heptane burns very explosively, which is the source of engine knocking. Although heptane is not desirable in automotive fuel, actual gasoline is a complex mixture that does contain some heptane.

The second use of pure heptane is as a laboratory solvent. A good solvent should be able to dissolve the reagents (ingredients) of the chemical reaction, but not interfere with the reaction. Heptane does this well because it has almost zero reactivity with other molecules, and many organic molecules that won't dissolve in water will dissolve in heptane.

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

Register for a free trial

Are you a student or a teacher?
I am 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

Earning College Credit

Did you know… We have over 95 college courses that prepare you to earn credit by exam that is accepted by over 2,000 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 free for 5 days!
Create An Account
Support