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Alkanes

Hydrocarbons are organic compounds made of carbon and hydrogen. Hydrocarbons are the dominant compounds in crude oil. Most of these hydrocarbons are alkanes.

Alkane structure

Alkane structure

  • In alkanes, carbon atoms bond to four atoms (hydrogen or carbon).
  • We call them saturated hydrocarbons as all their bonds with other atoms are single bonds.
Alkane uses

Alkane uses

  • Alkanes have quite low reactivity, but they combust quite well.
    • This makes them useful as fuels.
General formula

General formula

  • Alkanes have the general formula CnH(2n+2)
    • E.g. if a hydrocarbon contained 7 carbon atoms, the number of hydrogen atoms would be (2 x 7) + 2 = 16
  • So, the formula for the hydrocarbon shown in the image would be C7H16
Reaction with chlorine

Reaction with chlorine

  • Although alkanes are quite unreactive, they will react with chlorine in the presence of UV light. The UV light activates the chlorine molecule, which starts the reaction.
  • The overall reaction is a substitution reaction, as one hydrogen atom on the hydrocarbon is replaced by chlorine.
  • The products formed are a chloroalkane and hydrogen chloride
Jump to other topics
1

States of Matter

2

Atoms, Elements & Compounds

3

Stoichometry

4

Electrochemistry

5

Chemical Energetics

6

Chemical Reactions

7

Acids, Bases & Salts

8

The Periodic Table

9

Metals

10

Chemistry of the Environment

11

Organic Chemistry

11.1

Formulae, Functional Groups & Terminology

11.2

Naming Organic Compounds

11.3

Fuels

11.4

Alkanes

11.5

Alkenes

11.6

Alcohols

11.7

Carboxylic Acids

11.8

Polymers

12

Experimental Techniques & Chemical Analysis

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