Introduction
In order to understand how to name hydrocarbons, you must learn how they are classified. This material is going to give you a little insight into how these compounds are classified.
Task
Read the text below and answer the questions on the next page!
Hydrocarbons are organic compounds which contain only carbon and hydrogen. By using this definition, four classes of hydrocarbons are included: alkanes, alkenes, alkynes and aromatic hydrocarbons.
Alkanes are considered saturated because they have only single C-C bonds and cannot add a hydrogen. Alkenes, alkadienes and alkyns are unsaturated because they are capable of adding a hydrogen when the C=C double or triple bond is broken.
| Alkanes | Alkenes | Alkadienes | Alkyns | |
| Type | SATURATED hydrocarbons which means that each carbon is bonded to four other atoms through single covalent bonds. | UNSATURATED hydrocarbons contain either double or triple bonds. | UNSATURATED | UNSATURATED |
| Bonds | Single bonds only | One double bond | Two double bonds | At least one triple bond |
|
General formula |
C n H 2 n+2 | C n H 2 n | C n H 2 n‐2 | C n H 2 n‐2 |
Examples:
Aromatic compounds
Aromatic compounds derive their names from the fact that many of these compounds in the early days of discovery were grouped because they were oils with fragrant odors, hence the name aromatic.
The current definition of aromatic compounds includes only those with a benzene ring, which is a special six carbon ring compound with three alternating double bonds. This structure imparts unique properties to benzene which are different from other ring compounds.
If needed you can open the link below and watch this video which explains everything listed above!
https://www.brightstorm.com/science/chemistry/organic-chemistry/hydrocarbons/
Process
After watching the video you should be able to answer these questions!
1.What's the main difference between saturated and unsaturated hydrocarbons?
2.Name one kind of saturated hydrocarbons.
3.What's the main difference between alkenes and alkadienes?
4.What kind of hydrocarbon is methane (CH4)?
5.What kind of hydrocarbon is ethene (C2H4)?
6.What is the general molecular formula of alkyns and alkadienes?
7.How many carbons are in a benzene ring?
8.How many double bonds are in a benzene ring?
9.What is the simplest hydrocarbon?
10.How many bonds can carbon form?
Evaluation
These are the answers to questions on the previous page.
1.Saturated carbons have only single bonds and they cannot add a hydrogen whereas unsaturated carbons can because they have double and triple bonds which can be broken.
2.Alkanes.
3.Alkenes have only one double bond, alkadienes have two.
4.Alkane.
5.Alkene.
6.CnH2n-2
7.6
8.3
9.Methane (CH4)
10.4
Conclusion
If you answered most of the questions correctly, congratulations! You now know how to classify hydrocarbons. You can continue learning more about naming them etc.
For more information there are various websites you could visit (such as khanacademy.org) and many books you could read.
Credits
The given material was taken from various websites such as cliffsnotes.com, brightstorm.com and chemistry.elmhurst.edu.