Class 10 Science

Carbon and Its Compounds Alkane

These notes are based on the chapter Carbon and its Compounds from class 10 science of NCERT book and CBSE syllabus.

  • General formula of alkane
  • Structural Formulae of methane to decane

Hydrocarbons having only single bonds are known as alkane. These are saturated hydrocarbons. Alkane are also known as paraffin.

General Formula of Alkane

CnH2n+2

Methane

If C = 1, then, CnH2n+2 = C1H2 × 1 + 2 = CH4

Name of this compound is methane. It can be shown by following structural formula:

structural formula methane

Ethane

If C = 2, then, CnH2n+2 = C2H2 × 2 + 2 = C2H6

Name of this compound is ethane. It can be shown by following structural formula:

structural formula ethane

Structural formula of ethane can also be written as CH3CH3 or CH3 − CH3

Propane

If C = 3, then, CnH2n+2 = C3H2 × 3 + 2 = C3H8

Name of this compound is propane. It can be shown by following structural formula:

structural formula propane

Butane

Structural formula of propane can also be written as CH3CH2CH3 or CH3 − CH2 − CH3

If C = 4, then, CnH2n+2 = C4H2 × 4 + 2 = C4H10

Name of this compound is butane. It can be shown by following structural formula:

structural formula butane

Structural formula of propane can also be written as CH3CH2CH2CH3 or CH3 − CH2 − CH2 − CH3

Pentane

If C = 5, then, CnH2n+2 = C5H2 × 5 + 2 = C5H12

Name of this compound is pentane. It can be shown by following structural formula:

structural formula pentane

Structural formula of pentane can also be written as CH3CH2CH2CH2CH3 or CH3 − CH2 − CH2 − CH2 − CH3

Hexane

If C = 6, then, CnH2n+2 = C6H2 × 6 + 2 = C6H14

Name of this compound is hexane. It can be shown by following structural formula:

structural formula hexane

Structural formula of hexane can also be written as CH3CH2CH2CH2CH2CH3 or CH3 − CH2 − CH2 − CH2 − CH2 − CH3

Heptane

If C = 7, then, CnH2n+2 = C7H2 × 7 + 2 = C7H16

Name of this compound is heptane. It can be shown by following structural formula:

structural formula heptane

Structural formula of heptane can also be written as CH3CH2CH2CH2CH2CH2CH3 or CH3 − CH2 − CH2 − CH2 − CH2 − CH2 − CH3

Octane

If C = 8, then, CnH2n+2 = C8H2 × 8 + 2 = C8H18

Name of this compound is octane. It can be shown by following structural formula:

structural formula octane

Structural formula of octane can also be written as CH3CH2CH2CH2CH2CH2CH2CH3 or CH3 − CH2 − CH2 − CH2 − CH2 − CH2 − CH2 − CH3

Nonane

If C = 9, then, CnH2n+2 = C9H2 × 9 + 2 = C9H20

Name of this compound is nonane. It can be shown by following structural formula:

structural formula nonane

Structural formula of nonane can also be written as CH3CH2CH2CH2CH2CH2CH2CH2CH3 or CH3 − CH2 − CH2 − CH2 − CH2 − CH2 − CH2 − CH2 − CH3

Decane

If C = 10, then, CnH2n+2 = C10H2 × 10 + 2 = C10H22

Name of this compound is decane. It can be shown by following structural formula:

structural formula decane

Structural formula of decane can also be written as CH3CH2CH2CH2CH2CH2CH2CH2CH2CH3 or CH3 − CH2 − CH2 − CH2 − CH2 − CH2 − CH2 − CH2 − CH2 − CH3

  • Methane: CH4
  • Ethane: C2H6
  • Propane: C3H8
  • Butane: C4H10
  • Pentane: C5H12
  • Hexane: C6H14
  • Heptane: C7H16
  • Octane: C8H18
  • Nonane: C9H20
  • Decane: C10H22

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