Chapter3

Chapter Three: Chemical Bonds

Chemical Bonds Overview

  • Types of Chemical Bonds:

    • Ionic Bond: Forms compounds between a metal and a non-metal.

    • Covalent (Molecular) Bond: Forms compounds of non-metals.

Ionic Bonds

  • Definition: Strong attraction that connects two atoms through the exchange of electrons between two charged atoms.

    • Role of Ions:

      • Cation: Positively charged atom.

      • Anion: Negatively charged atom.

  • Formation: The attraction between sodium cation (Na+) and chloride anion (Cl-) demonstrates this bond.

  • Characteristics:

    • Charges must cancel, resulting in a neutral compound.

    • Steps to determine the formula for compounds, for example, aluminum (Al) and sulfur (S):

      1. Determine charge on each ion: Al+3 and S-2.

      2. Write the ions: Al3 and S2.

      3. Exchange the numbers to form formula: Al2S3.

    • Erase the signs in the final formula.

Naming Inorganic Compounds

Binary Ionic Compounds

  • Cation Naming: Retains the element name.

  • Anion Naming: Ends with -ide.

  • Example:

    • For FeCl2: Iron (II) Chloride.

    • For FeCl3: Iron (III) Chloride.

Polyatomic Ions and Compounds

  • Polyatomic Ions: Groups of atoms that must appear together in a compound.

  • Naming Convention: If there is more than one polyatomic ion, enclose the radical in parentheses when required.

    • Example: (NH4)2SO4.

  • Common Acids:

    • Hydrochloric Acid (HCl)

    • Phosphoric Acid (H3PO4)

    • Acetic Acid (HC2H3O2)

    • Nitric Acid (HNO3)

    • Sulfuric Acid (H2SO4)

Covalent Compounds

  • Definition: Formed when two atoms share a pair of electrons.

  • Characteristics:

    • Generally occurs between two non-metals.

    • Naming involves using prefixes to indicate quantity (di-, tri-, etc.).

      • Exception: Mono is not used for the first atom in a compound (CO is carbon monoxide).

Inorganic Nomenclature Summary

  1. Ionic Compounds:

    • Metal + Non-metal

    • Simple and Complex (e.g., Transition Metals, Polyatomic Compounds)

  2. Acids:

    • Names must be memorized.

  3. Molecular Compounds:

    • Formed from two non-metals.