Difference Between Olefins and Paraffins

The key difference between olefins and paraffins is that olefins essentially contain one or more double bonds between carbon atoms, whereas paraffins do not contain any double or triple bond between carbon atoms.

Olefin and paraffin are common terms for two different groups of hydrocarbon compounds. Olefins are alkenes, and paraffins are alkanes. These two terms, olefin and paraffin, are used mainly in industrial applications.

CONTENTS

1. Overview and Key Difference
2. What are Olefins 
3. What are Paraffins
4. Side by Side Comparison – Olefins vs Paraffins in Tabular Form
5. Summary

What are Olefins?

Olefins are alkenes. They contain one or more double bonds between carbon atoms. An olefin is a group of hydrocarbons composed of only carbon and hydrogen atoms. Olefin is another name for alkenes since olefins are hydrocarbons that are composed of carbon atoms with double bonds. Therefore, olefins are composed of sp³ hybridized carbon atoms as well as sp² hybridized carbon atoms. Moreover, they are unsaturated hydrocarbon compounds.

Olefins have C-H single bonds, C-C single bonds, and C=C double bonds. There can be several different combinations of carbon and hydrogen atoms. But all these combinations are represented by the general formula of olefins, which is C_nH_2n where n is a whole number.

Olefins can be categorized in several different ways. Cyclic structures are known as cyclic olefins. Aliphatic structures are called acyclic olefins. By the number of double bonds present in the chemical structure, olefins can be named as monoolefins, diolefins, triolefins, etc.

Olefins can be found in all three phases of matter depending on their chemical structures. Simple olefins exist as gases, whereas complex olefins exist as liquids or solids. Due to their high chemical reactivity, olefins occur in very limited amounts in crude oil and natural gases. Olefins can be produced in refineries during crude oil processing. Here, olefins are produced by cracking processes. For example, thermal cracking is a major reaction that can be used to obtain olefins from petroleum oil.

What are Paraffins?

Paraffins are alkanes, which are saturated hydrocarbons having the chemical formula C_nH_2n+2 (where n is a whole number). These are called hydrocarbons because they contain C and H atoms. All these atoms are linked to each other via single covalent bonds. Since there are no double or triple bonds, paraffins are saturated hydrocarbons.

Further, these compounds are a broad group of organic molecules. We can name them according to the number of carbon atoms and the side groups that they are comprised of. The smallest alkane is methane. In methane, a central carbon atom binds with 4 hydrogen atoms. The IUPAC nomenclature of paraffins is based on Greek prefixes.

All paraffins are colourless and odourless. The melting points and boiling points increase with the increase of the number of carbon atoms. Under standard temperature and pressure conditions, some of them are liquids, while some are gaseous compounds. And, this difference is due to their different boiling points. Moreover, alkanes show isomerism. A paraffin molecule may have structural isomerism or stereoisomerism according to its structure and spatial arrangement of the molecule.

What is the Difference Between Olefins and Paraffins?

Olefin and paraffin are common terms for two different groups of hydrocarbon compounds. Olefins are alkenes while paraffins are alkanes. Therefore, the key difference between olefins and paraffins is that olefins essentially contain one or more double bonds between carbon atoms, whereas paraffins do not contain any double or triple bond between carbon atoms. Furthermore, the general formula for olefins is CnH2n while the formula for paraffins is CnH2n+2. Moreover, olefins can undergo polymerization due to the presence of pi bonds, but paraffins cannot undergo polymerization due to absence of pi bonds.

Summary – Olefins vs Paraffins

The term olefin and paraffin are common terms for two different groups of hydrocarbon compounds. Olefins are alkenes, and paraffins are alkanes. Therefore, the key difference between olefins and paraffins is that olefins essentially contain one or more double bonds between carbon atoms, whereas paraffins do not contain any double or triple bond between carbon atoms.

Reference:

1.  “Paraffin Hydrocarbon.” Encyclopædia Britannica, Encyclopædia Britannica, Inc., Available here.

Image Courtesy:

1. “IUPAC-alkene” By Fvasconcellos 20:06, 8 January 2008 (UTC). Original image by DrBob (talk · contribs). – Vector version of Image:Iupac-alkene.png by DrBob (talk · contribs) (CC BY-SA 3.0) via Commons Wikimedia
2. “Methane-2D-stereo” By SVG version by Patricia.fidi – Own work (Public Domain) via Commons Wikimedia