11.1.2

General Formulae of Organic Compounds

Test yourself

General Formulae of Organic Compounds

A homologous series groups organic compounds with similar structure, same functional group, and differ by CH2 units. These include alkanes, alkenes, alcohols, and carboxylic acids.

Illustrative background for What is a homologous series?Illustrative background for What is a homologous series? ?? "content

What is a homologous series?

  • A homologous series is a group of organic compounds.
  • Compounds in a homologous series have similar structures.
  • Each member of the series differs from the next by a -CH2- unit in the chain.
    • Members have the same functional group.
    • Example: Alkanes, alkenes, alcohols, carboxylic acids.
Illustrative background for General formula of alkanes (C<sub>n</sub>H<sub>2n+2</sub>)Illustrative background for General formula of alkanes (C<sub>n</sub>H<sub>2n+2</sub>) ?? "content

General formula of alkanes (CnH2n+2)

  • Alkanes are saturated hydrocarbons.
  • Alkanes only have carbon and hydrogen.
  • Alkanes have single bonds only.
    • The general formula is CnH2n+2.
Illustrative background for General formula of alkenes (C<sub>n</sub>H<sub>2n</sub>)Illustrative background for General formula of alkenes (C<sub>n</sub>H<sub>2n</sub>) ?? "content

General formula of alkenes (CnH2n)

  • Alkenes are unsaturated hydrocarbons.
  • Alkenes have a double bond between adjacent carbon atoms.
    • The general formula is CnH2n.
  • Alkenes react differently from alkanes due to double bonds.
Illustrative background for General formula of alcohols (C<sub>n</sub>H<sub>2n</sub>+1OH)Illustrative background for General formula of alcohols (C<sub>n</sub>H<sub>2n</sub>+1OH) ?? "content

General formula of alcohols (CnH2n+1OH)

  • Alcohols contain an –OH group (hydroxyl).
  • Alcohols have hydrocarbons plus OH.
    • The general formula is CnH2n+1OH.
  • Alcohols can dissolve in water and burn.
Illustrative background for General formula of carboxylic acids (C<sub>n</sub>H<sub>2n</sub>+1COOH)Illustrative background for General formula of carboxylic acids (C<sub>n</sub>H<sub>2n</sub>+1COOH) ?? "content

General formula of carboxylic acids (CnH2n+1COOH)

  • Carboxylic acids have a –COOH group.
  • They have the functional group carboxyl.
    • The general formula is CnH2n+1COOH.
  • Carboxylic acids taste sour and react with carbonates.

Jump to other topics

1States of Matter

2Atoms, Elements & Compounds

3Stoichometry

4Electrochemistry

5Chemical Energetics

6Chemical Reactions

7Acids, Bases & Salts

8The Periodic Table

9Metals

10Chemistry of the Environment

11Organic Chemistry

11.1Formulae, Functional Groups & Terminology

11.2Naming Organic Compounds

11.3Fuels

11.4Alkanes

11.5Alkenes

11.6Alcohols

11.7Carboxylic Acids

11.8Polymers

12Experimental Techniques & Chemical Analysis

Unlock your full potential with Seneca Premium

  • Unlimited access to 10,000+ open-ended exam questions

  • Mini-mock exams based on your study history

  • Unlock 800+ premium courses & e-books

Get started with Seneca Premium