Difference Between Alkanes, Alkenes and Alkynes (With Table)

Compounds containing hydrogen and carbon are known as hydrocarbons. Different types of chemical bonds bind these atoms with each other in molecule form. Alkanes, alkenes, as well as alkynes, are the three main kinds of hydrocarbons.

Alkanes vs Alkenes vs Alkynes

The main difference between alkanes, alkenes, and alkynes is the fact that alkanes create a single bond between carbon atoms, whereas alkenes form a double bond, and alkynes make a triple bond.

Difference Between Alkanes Alkenes and Alkynes

Alkane is also called paraffin. Hydrogen atoms complete the valencies of all of the four carbon atoms. Methane, ethane, and even propane are the most basic alkanes. It’s employed in a variety of industrial procedures.

Alkenes are referred to as dienes, whereas alkenes are referred to as alkenes. Due to the existence of a double bond, they are unsaturated hydrocarbons. They may be integrated into cycloalkenes of various diameters. Ethene, propene, and many other alkenes are the most basic and may be made in the laboratory.

Alkynes, however, are known as trienes. Alkynes are very flammable, and the simplest alkynes exist in a gaseous state; but, as the complex grows larger, it can exist as liquids or even solids.

Comparison Table Between Alkanes, Alkenes, and Alkynes

Parameters of comparisonAlkaneAlkeneAlkynes
Bond joining carbon atomsSingleDoubleTriple
Physical propertiesThey are colorless, have a low molecular weight, and have a high boiling point. They can be solids, liquids, or gases. At room temperature, it is colorless, nonpolar, flammable, and has a strong odor. It exists as a gas and has a higher molecular mass.With the exception of alkynes, which have a distinct odor, they are odorless and colorless and have a high melting and boiling point due to their larger molecular structure.
Chemical propertiesAre weak acids that react to electrophilic reagents and react to oxygen and hydrogen, but just don’t react with some other chemical compounds as well as free radicals.The lengthier molecular structure of alkenes has a high boiling point and also the polarization of alkanes is determined by functional groups.Alkenes are less water-soluble and have a higher boiling point.
It’s somewhat acidic, electronegative, and flammable.
ApplicationLiquefied petroleum gas (LPG), natural gas, aerosol sprays, combustion engines, and other applications. Plastic, liquor, fuels, ethanol, acrylic acids, glycerol ester, artificial rubbers, and crude oil and natural gas production, among other thingsPolymer, PVC, and rubber synthesis are used in medical, pharmaceuticals, as well as other drug manufacturing applications. It is often used in industry to ripen fruits and do other activities.
InstanceEthaneEtheneEthyne

What is Alkane?

Alkanes are a form of saturated hydrocarbon with a tree structure of hydrogen and carbon atoms. Alkanes have solitary carbon-carbon bonds. Alkanes are “acyclic branched as well as unbranched hydrocarbons having a general formula, CnH (2n+2),” according to the IUPAC (International Union of Pure and Applied Chemistry).

Alkane hybridization is classified as sp3. It has four bond indicators and is connected by carbon atoms. The carbon skeleton is the greatest chain with carbon atoms connected together and is used to calculate the size of an alkane.

Alkanes are sometimes known as paraffin because they have wax-like properties when exposed to specific temperatures and pressures (SATP). Alkanes are divided into three types based on their structure: linear, branching, and cyclic alkanes.

If an alkane has even more than three carbon atoms, it may be structured in a variety of configurations, which is what structural isomers are made of. Petroleum, crude oil, or natural gas all include alkanes. Methane, ethane, propane, butane, pentane, hexane, heptane, octane, and other kinds of alkanes.

What is Alkene?

Alkenes are unsaturated hydrocarbons with a double bond between carbon and carbon. They are apolar and highly reactive chemicals. A sigma bond, as well as a pi bond, connects the carbon atoms’ double bonds. Unlike most single covalent bonds, this one is extremely strong and stable.

The double bond is not as long as the single bond. Alkenes have a bond length of 133 pm (1.33). sp2 is the hybridization of alkenes. Because of the high energy cost of breaking, the alkenes need not readily spin. An alkene’s bond angles are around 120 degrees apart.

Alkenes are stable molecules that go through a variety of processes such as addition, hydrogenation, hydrolysis, halogenation, hydrohalogenation, oxidizing, halohydrin production, polymerization, metallic complexation, alkylation, and many more.

Plastic, wine, fuels, vinyl chloride, acrylic acids, glycerol ester, artificial rubbers, oil and natural gas production, and a variety of other industrial processes all employ alkynes. Ethene, propene, butene, pentene, hexene, heptene, and various isomers are examples of alkenes.

What is Alkyne?

Alkanes are unsaturated hydrocarbons with a carbon triple bond. Initially, alkynes were classified as acetylenes. The angle of the carbon atoms’ bonds is 180°. The structure of the alkynes is rod-like. Olefins is another name for them.

The C-atoms have an extremely small bond length of 121 pm. The triple bond seems to have a high bond strength of around 839 kJ/mol. It possesses a sp hybridization, which means that the s and p orbitals intersect and create three bonds.

After that, an “ene” suffix is added to the name of the alkyne. Alkynes can be made using a variety of methods, including cracking and dehydrohalogenation. Alkynes are a volatile functional group that can undergo hydrogenation, halogen addition, hydrolysis, tautomerism, or cycloaddition.

Alkynes are commonly utilized in pharmaceuticals, medications, and other drug production applications. Also used in the manufacture of polymers, PVC, and rubber. It’s a term that’s often used in the industry to describe ripe fruits. Propyne, butyne, pentyne, as well as other alkynes, are examples.

Main Differences Between Alkanes, Alkenes, and Alkynes

  1. Alkanes have the chemical formula Cn H(2n+2), whereas alkenes have the formula Cn H2n and alkynes have the formula Cn H. (2n-2).
  2. Alkane hybridization is sp3, whereas alkene hybridization is sp2 and alkynes hybridization is sp.
  3. Saturated hydrocarbons are alkanes, while unsaturated hydrocarbons are alkanes and alkynes.
  4. Paraffins are alkanes, whereas olefins are alkanes and alkenes.
  5. Alkanes have a Van der Waals dispersion force, whereas alkenes have a weak dipole-dipole interaction, whereas alkynes have London dispersion forces as intermolecular interactions.
  6. Alkanes have a bond length of 153 pm, alkenes have a bond length of 134 pm, and alkynes have a bond length of 121 pm.

Conclusion

Alkanes, alkenes, as well as alkynes, are hydrocarbons that do not contain any functional groups. Instead, they’re chains of carbon atoms, usually in a single plane, with no other functional groups attached. They appear to be similar substances, yet they are not.  It is important to appreciate the distinction so that a better understanding of polymerization is achieved. There are subtypes beneath each kind, which are researched in depth under the subject.

References

  1. https://pubs.rsc.org/en/content/articlehtml/2009/cc/b820048chttps://aip.scitation.org/doi/abs/10.1063/1.1680347
  2. https://pubs.rsc.org/en/content/articlehtml/2009/cc/b820048chttps://aip.scitation.org/doi/abs/10.1063/1.1680347