Difference Between Alkanes and Alkenes

Main difference

The main difference between alkanes and alkenes is that alkanes are the hydrocarbons in which the main chain of a carbon atom contains a single bond while alkenes are the hydrocarbons in which the main carbon chain contains a double bond. ..

Alkanes vs. Alkenes

Alkanes are saturated hydrocarbons, while alkenes are unsaturated hydrocarbons. Alkanes are the hydrocarbons that contain a single bond in the main chain, while alkenes are the hydrocarbons that contain multiple bonds of a double bond. The general formula for alkanes is C n H 2n + 2 , while the general formula for alkenes is C n H 2n .

The polymerization process is not common in alkanes while the polymerization process is very common in alkenes. Alkanes contain only sigma bonds and no pi bonds on the other hand, alkenes contain both sigma and pi bonds in the carbon chain. Alkanes undergo substitution reactions while alkenes undergo addition reactions. Alkanes do not undergo electrophilic addition reactions; on the other hand, alkenes can undergo electrophilic addition.

Alkanes undergo free radical mechanisms, while such a reaction is not common in alkenes. Alkanes do not change the brown color of brominated water, while alkenes can change the brown color of brominated water to colorless. Alkanes show no reaction with alkaline or acidic KMnO 4 , while alkenes show reaction with alkaline or acidic KMnO 4 and change the purple color of the solution.

Alkanes are considered less reactive towards electrophilic agents; on the other hand, alkenes are considered more reactive towards electrophilic agents. Alkanes are less reactive as there is less chance of availability of electrons; on the other hand, alkenes are more reactive as there are more chances for free electrons to be available.

Alkanes can show reactions only in the presence of sunlight, while alkenes can show reactions in both the existence and deficiency of sunlight. An example of alkanes is ethane while the example of alkenes is ethene.

Comparison chart

alkanes alkenes
Alkanes are hydrocarbons in which the backbone of a carbon atom contains a single bond. Alkenes are hydrocarbons in which the main carbon chain contains a double bond.
hydrocarbons
Saturated unsaturated
General Formula
n H 2n + 2 CnH2n _ _ _
bond numbers
simple link double bond
Reactivity
less reactive more reactive
Types of bonds
sigma link only sigma and pi bond
reactions
May show a substitution reaction. May show addition reaction.
Sunlight
Only in the presence of sunlight Absence or presence of sunlight
Example
ethane Ethene

What are alkanes?

Saturated hydrocarbons contain only one single bond in the main carbon bond. Alkanes contain only one sigma bond and the pi bond is absent in alkanes. That is why it decreases the chances of availability of electrons in the compound. For this reason, alkanes are considered less reactive towards electrophile agents.

It can’t show addition reaction in biochemistry. It can only give substitution reactions and free radical mechanisms. It is also used in the production of many different organic compounds in chemistry. But you can only give this type of reaction in the presence of sunlight or ultraviolet light or in the presence of catalysts.

It cannot give bromine water solution reactions in the presence of CCl 4 and cannot change its reddish-brown color of the solution. He has no proof of identification. Alkanes also do not form precipitation in ammonia water solution. Examples of alkanes are methane, ethane, propane, butane, pentane, etc. are included in the examples of alkanes.

What are alkenes?

Unsaturated hydrocarbons contain multiple bonds, such as the triple bond in the main carbon bond. Alkenes contain sigma and pi bonds in the compound. It increases the chances of availability of electrons in compounds. Due to these reasons, alkenes are more reactive towards electrophilic reagents than alkanes and alkynes.

You can show additional reactions in chemistry labs. It can also give other reactions such as dehydration, polymerization processes, etc. You can give these reactions in the presence or absence of light or in the presence of catalysts, you can give better reactions.

It may show reaction with bromine water and may change the color of bromine from reddish-brown to colorless. It also gives reactions to an ammonia water solution. Examples of alkenes are ethene, propene, butene, etc. are included in the examples of alkenes.

Key differences

  1. Alkanes fall under the category of saturated hydrocarbons, while alkenes fall under the category of unsaturated hydrocarbons.
  2. Alkanes are the saturated hydrocarbons consisting of a single bond in the main carbon chain while alkenes are the unsaturated hydrocarbons consisting of multiple bonds of the double bond in the main carbon chain.
  3. The general formula for alkanes is C n H 2n + 2 , while the general formula for alkenes is C n H 2n .
  4. The polymerization process does not occur in hydrocarbons of alkanes, while the polymerization process generally occurs in hydrocarbons of alkenes.
  5. Only one sigma bond is present in the carbon chain of alkanes; on the other hand, both sigma and pi bond are present in the carbon chain of alkenes.
  6. Alkanes face substitution reaction while alkenes go through addition reaction.
  7. Alkanes do not undergo electrophilic addition reactions; on the other hand, alkenes can go through electrophilic addition.
  8. Free radical mechanisms occur in alkanes while free radical mechanism does not occur in alkenes.
  9. Alkanes do not change the brown color of brominated water, while alkenes can change the color of brominated water from brown to colorless.
  10. Reaction with alkaline or acidic KMnO 4 is not common in alkanes, while alkenes react with alkaline or acidic KMnO 4 and change the purple color of the solution.
  11. Alkanes are believed to be less reactive in the presence of electrophilic agents; on the other hand, alkenes are believed to be more reactive in the presence of electrophiling agents.
  12. Alkanes are less reactive in chemical reactions; on the other hand, alkenes are more reactive in chemical reactions.
  13. Alkane reactions occur only in the presence of sufficient sunlight, while alkene reactions occur in both the absence and presence of sunlight.
Final Thoughts

The above discussion concludes that both alkanes and alkenes are types of hydrocarbons. Alkanes are the hydrocarbons that contain only one sigma bond in the main carbon chain while alkenes are the hydrocarbons that contain both sigma and pi bonds in the main carbon chain.

Related Articles

Leave a Reply

Your email address will not be published. Required fields are marked *

Back to top button