Chapter Three: Molecules and Compounds - Organic Compounds

Chapter Three: Molecules and Compounds

Lesson Six: Organic Compounds (3.11)

• Origins of Classification

  • Early chemists categorized compounds into two main classes:

  • Organic: Derived from living organisms.

    • Example: "sugar from sugar cane".

  • Inorganic: Derived from non-living sources like the earth.

    • Example: "salt from ground/earth".

  • Assumptions of Early Chemists

  • Organic compounds were believed to be easily decomposed.

  • Thought to be impossible to synthesize in a lab.

  • Inorganic compounds were seen as harder to decompose but could be synthesized.

  • Modern Understanding

  • Today, many organic compounds can be synthesized in the lab.

  • Organic compounds are ubiquitous, forming the basis of life.

  • Major components of living organisms predominantly composed of:

    • Carbon (C)

    • Hydrogen (H)

    • Sometimes Oxygen (O), Nitrogen (N), Sulfur (S), and trace amounts of other elements.

Carbon Bonding

• Role of Carbon

  • Carbon is the essential element in organic chemistry.

  • It forms covalent bonds in organic compounds, enabling a variety of molecular structures.

• Bonding Characteristics of Carbon

  • Each carbon atom forms four covalent bonds.

  • Bonds can be:

  • Single bonds

  • Double bonds

  • Triple bonds

  • Versatility of Carbon

  • Capable of bonding with itself:

    • Forms extensive chains of C atoms.

    • Structures can be:

    • Straight

    • Branched

    • Ringed

Classification of Organic Compounds

• Types of Organic Compounds

  • Broadly categorized into two groups:

  • Hydrocarbons

  • Functionalized hydrocarbons

Hydrocarbons

• Definition

  • Compounds that contain only carbon (C) and hydrogen (H).

• Common Uses

  • Compose typical fuels such as:

  • Gasoline

  • Liquid propane gas

  • Natural gas

• Classification of Hydrocarbons

  • Aliphatic Hydrocarbons

  • Include:

    • Alkanes

    • Alkenes

    • Alkynes

    • Cycloalkanes

    • Cycloalkenes

  • Aromatic Hydrocarbons

  • Include Benzene and its substituted derivatives.

Functionalized Hydrocarbons

• Definition

  • Compounds that contain carbon, hydrogen, and additional elements (such as O, N, S).

• Identification

  • Distinguished by specific functional groups:

  • Hydroxyl (
    3-OH)

  • Carboxyl (
    3-COOH)

  • Amino (
    3-NH2)

• Classification

  • Functionalized hydrocarbons are further categorized based on the additional elements they contain:

  • Oxygen-containing products:

    • Alcohols

    • Ethers

    • Aldehydes

    • Carboxylic acids

  • Nitrogen-containing products:

    • Amines

    • Amides

    • Nitriles

  • Sulfur-containing products:

    • Thiols

    • Thioethers

Example Classification of Organic Compounds

• Exercise: Classify the following

  • a) Propane (
    3-C3H8): Hydrocarbon

  • b) Methanol (
    3-CH3OH): Functionalized Hydrocarbon

  • c) Acetic acid (
    3-CH3COOH): Functionalized Hydrocarbon

  • d) Octane (
    3-C8H18): Hydrocarbon

  • e) Ethanethiol (
    3-CH3CH2SH): Functionalized Hydrocarbon

Common Hydrocarbons

Common Functionalized Hydrocarbons