Alkanes vs. Alkenes: What's the Difference?
Edited by Janet White || By Harlon Moss || Updated on October 20, 2023
Alkanes are saturated hydrocarbons with single bonds only, while alkenes are unsaturated hydrocarbons with at least one double bond.
Key Differences
Alkanes, sometimes termed as paraffins, are hydrocarbons where all carbon-carbon bonds are single, indicating full saturation. In contrast, alkenes, also known as olefins, are hydrocarbons that contain at least one carbon-carbon double bond, showcasing unsaturation.
The presence of a double bond in alkenes makes them generally more reactive than alkanes. Alkanes, with their single bonds, tend to be less reactive and more stable under standard conditions. This difference in reactivity means that alkanes and alkenes undergo different types of chemical reactions.
In terms of nomenclature, alkanes use the suffix "-ane" (like methane, propane), while alkenes use the suffix "-ene" (like ethene, propene). This linguistic differentiation provides a clue to their structural differences and is useful for quick identification.
The physical properties of alkanes and alkenes also differ. Alkanes, for instance, are generally less dense than water and are not very soluble in it. Alkenes, although sharing some similar properties with alkanes, might have slightly different boiling and melting points due to the presence of a double bond.
From a source perspective, alkanes are abundant in natural gas and petroleum, and their combustion is a primary energy source. Alkenes, while also found in petroleum, are usually synthesized for industrial uses, leveraging their reactivity.
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Comparison Chart
Bond Type
Single carbon-carbon bonds.
At least one carbon-carbon double bond.
Saturation
Saturated hydrocarbons.
Unsaturated hydrocarbons.
Reactivity
Generally less reactive.
More reactive due to double bonds.
Nomenclature
Uses the suffix "-ane".
Uses the suffix "-ene".
Sources
Abundant in natural gas and petroleum.
Found in petroleum; often synthesized for industrial use.
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Alkanes and Alkenes Definitions
Alkanes
Organic compounds with only carbon and hydrogen atoms.
Pentane is an alkane with five carbon atoms.
Alkenes
Unsaturated hydrocarbons with at least one double bond.
Ethene, commonly known as ethylene, is a simple alkene.
Alkanes
Saturated hydrocarbons with only single bonds.
Methane and ethane are examples of alkanes.
Alkenes
Hydrocarbons with the general formula CnH2n.
Propene has the formula C3H6, adhering to the alkene general formula.
Alkanes
Hydrocarbons with the general formula CnH2n+2.
Propane, an alkane, has the chemical formula C3H8.
Alkenes
More reactive than alkanes due to the presence of double bonds.
Alkenes can participate in addition reactions because of their double bond.
Alkanes
Chemical compounds predominantly found in natural gas and oil.
The combustion of alkanes provides significant energy.
Alkenes
Hydrocarbons that can undergo polymerization.
Polyethylene is produced from the polymerization of ethene molecules.
Alkanes
Stable compounds due to the absence of double or triple bonds.
Alkanes are less reactive than their unsaturated counterparts.
Alkenes
Organic compounds used widely in the petrochemical industry.
Ethene is used in the production of polyethylene plastics.
Alkanes
Any member of the alkane series.
Alkenes
Any of a series of unsaturated, aliphatic hydrocarbons with a carbon-carbon double bond, having the general formula CnH2n.
Alkanes
Plural of alkane
Alkenes
Plural of alkene
FAQs
What type of bonds do alkanes possess?
Alkanes have single carbon-carbon bonds.
How can you distinguish between an alkane and an alkene by name?
Alkanes have names ending in "-ane" while alkenes end in "-ene".
Are alkanes found in natural gas?
Yes, alkanes are major constituents of natural gas.
Can alkenes be used to make plastics?
Yes, alkenes like ethene are used to make plastics like polyethylene.
How are alkenes used in the chemical industry?
Alkenes are key reactants in many chemical processes, including polymerization.
Which is generally more reactive, alkanes or alkenes?
Alkenes are generally more reactive due to the presence of a double bond.
Why are alkanes termed as saturated hydrocarbons?
Because alkanes have only single bonds, filling all available bond sites.
What is the general formula for alkanes?
The general formula for alkanes is CnH2n+2.
Which is more stable under standard conditions, alkanes or alkenes?
Alkanes are generally more stable because they lack double bonds.
What role do alkenes play in polymer production?
Alkenes can undergo polymerization to produce plastics and other polymers.
Are alkenes saturated or unsaturated hydrocarbons?
Alkenes are unsaturated hydrocarbons.
How does the presence of a double bond affect the properties of alkenes?
The double bond makes alkenes more reactive and can alter physical properties like boiling points.
Can alkanes undergo combustion?
Yes, alkanes can burn in oxygen to produce carbon dioxide and water.
Is it possible for alkanes to have a ring structure?
Yes, cyclic alkanes have a ring structure.
Why are alkenes called olefins?
"Olefin" is an older term for alkenes, referring to oils produced from them.
Do alkanes and alkenes have similar sources?
Both can be found in petroleum, but alkanes are also major components of natural gas.
Are alkenes found in everyday products?
Yes, alkenes are used in the production of many polymers found in everyday products.
Can alkenes be turned into alkanes?
Yes, through a process called hydrogenation, alkenes can be converted into alkanes.
How does the presence of double bonds affect the reactivity of alkenes?
The double bond in alkenes makes them more reactive, allowing them to undergo addition reactions.
How do the boiling points of alkanes and alkenes compare?
Alkanes and alkenes have similar boiling points, but the presence of a double bond can slightly alter an alkene's boiling point.
About Author
Written by
Harlon MossHarlon is a seasoned quality moderator and accomplished content writer for Difference Wiki. An alumnus of the prestigious University of California, he earned his degree in Computer Science. Leveraging his academic background, Harlon brings a meticulous and informed perspective to his work, ensuring content accuracy and excellence.
Edited by
Janet WhiteJanet White has been an esteemed writer and blogger for Difference Wiki. Holding a Master's degree in Science and Medical Journalism from the prestigious Boston University, she has consistently demonstrated her expertise and passion for her field. When she's not immersed in her work, Janet relishes her time exercising, delving into a good book, and cherishing moments with friends and family.
