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             All students know that Alkanes are very important topic in chemistry. To learning Alkane is compulsory, there is no any objection for that. So, in this article we will discuss about the- What is Alkane? Formula of Alkane, What are the properties of alkanes? Some uses and applications of alkanes etc.

  What is alkane?

          In simple words, alkanes are the aliphatic hydrocarbons with 'C-C' single bond. That is Alkanes are saturated compounds. 

OR

            Alkanes are non-cyclic but possibly branched saturated hydrocarbons with general molecular formula - C(n)H(2n+2).

Formula of Alkanes:

C(n)H(2n+2) is the formula or alkanes, where C= carbon atoms, H= Hydrogen atoms and n= any natural number.

So, the first 4 alkanes named as-

Methane: CH₄

Ethane: CH₃-CH₃

Propane: CH₃-CH₂-CH₃

Butane: CH₃-CH₂-CH₂-CH₃

             Alkanes with larger than 4 carbon atoms, the name of the non-branched molecule is formed from the corresponding Greek numeric prefix and the ending with -ane.

Examples:

Octane: C₈H₁₈

Hexadecane: C₁₆H₃₄

          If alkanes are cyclic, they are known as Cycloalkanes with molecular formula has two hydrogen atoms less than the corresponding non cyclic alkane, e.g. Cyclopentane C₅H₁₀.

Some Properties of  Alkanes:

  1) Alkanes are not highly reactive & have small biological activity; that is all alkanes are colourless and odourless.

2) Alkanes both alkanes and cycloalkanes are virtually not soluble in water but soluble in organic solvents. However, liquid alkanes are good solvents for many other non-ionic organic compounds.

3) Alkanes are not highly reactive when compared with other chemical substances. This is because the backbone carbon atoms in alkanes have attained their octet of electrons through forming four covalent bonds (the maximum allowed number of bonds under the octet rule; which is why carbon's valence number is 4). These 4 bonds produced by carbon in alkanes are sigma bonds, that are more stable than other types of bond because of the greater overlap of carbon's atomic orbitals with neighbouring atoms' atomic orbitals. To form alkanes react, the input of additional energy is required; either through heat or radiation.

4) Gasoline is a mixture of the alkanes and unlike several chemicals, can be stored for longer time and transferred without a problem. It is only when ignited that it has enough energy to continue reacting. This property makes it harder for alkanes to be converted into other types of organic molecules. .

5) Alkanes are less denser than water, as one can observe, oil, an alkane, floats on water.

6) Alkanes are non-polar solvents. Since only Carbon and Hydrogen atoms are present. Alkanes are immiscible in water but freely miscible in other non-polar solvents. Alkanes containing of weak dipole-dipole bonds that can't break the strong hydrogen bond between water molecules therefore it is not miscible in water. The same character is also shown by alkenes. Because alkanes contain only carbon and hydrogen, combustion produced compounds that consisting only carbon, hydrogen, or maybe oxygen. Like other hydrocarbons, combustion under most circumstances forming majorly carbon dioxide and water. However, alkanes needed maximum heat to combust and do not release as much heat when they combust as other classes of hydrocarbons. Therefore, the combustion of alkanes produces higher concentrations of organic compounds containing oxygen, such as aldehydes and ketones, when combusting at the equal temperature as other hydrocarbons.

What are some uses and applications of alkanes?

1) METHANE (CH4):

          It is used as a fuel for homes, ovens, water heaters, kilns and automobiles as it combust with oxygen to produce heat. Also used for electricity generation. 

              As a vehicle fuel in the form of liquefied natural gas (LNG). It is highly environment friendly than gasoline, petrol and diesel.  Refined liquid methane is used as rocket fuel.

2. ETHANE (C2H6):

      Used in the preparation of ethene and certain heavier hydrocarbons. Ethane also used as a refrigerant in cryogenic refrigeration systems.

Used to prepare ethylene, that is used to preparation of  plastic, automotive antifreeze, and detergents etc.

3. PROPANE (C3H8):

Used as a domestic and industrial fuel.  
Propane is the primary fuel for hot air balloons.

         Propane powers locomotives, buses, forklifts, taxis, furnaces, water heaters, laundry dryers, barbecues, portable stoves, and motor vehicles etc.

Propane is mainly used in theme parks and in movies for explosions and special effects.

4. BUTANE (C4H10):

Butanee is a key ingredient of synthetic rubber.

It is used as a fuel in cigarette lighters.

When blended with propane and other hydrocarbons, it may be referred to commercially as LPG, for liquefiel petroleum gas.

Butane fuel canisters are used in camping stoves.

Also used in aerosol spray cans.
Butane gas cylinders are used in cooking.

5. PENTANE (C5H12):

Pentane is used in the production of polystyrene foams and other foams.
Used in laboratories as solvents.
They are also active ingredients of pesticides.

Used in liquid chromatography.

6. HEXANE (C6H14):

It is used in the formulation of glues for shoes, leather products, and roofing.
They are also used to extract cooking oils (such as canola oil or soy oil) from seeds.

Also for cleansing and degreasing a variety of items, and in textile manufacturing.

7. HEPTANE (C7H16):

Heptane is used in paints and coatings.
Pure n-heptane is used for research and development and pharmaceutical manufacturi

Also as a minor component of gasoline.
It is applied in laboratories as a non-polar solvent.

8. OCTANE (C8H18):

It is a component of gasoline (petrol).
Octane is vital in preventing engine damage.

9. NONANE (C9H20):

Nonane is also used as a solvent, distillation chaser, fuel additive, and a component in biodegradable detergent.
Used in automotive fuel and jet fuel.
Used as a component in organic solvents.

10. DECANE (C10H22) :

Decane is often used for industrial purposes.
It is commonly used in fuels such as gasoline.
Used as a synthetic solvent.