Lecture Notes: Ionic vs. Molecular (Covalent) Compounds

Identifying Ionic and Molecular Compounds

• Ionic Compounds

  • Made of metals and nonmetals.
  • Example: Sodium Chloride (NaCl) is ionic (Sodium: metal, Chlorine: non-metal).

• Molecular (Covalent) Compounds

  • Made of only nonmetals.
  • Example: Sulfur Dioxide (SO₂) is molecular (Sulfur and Oxygen: both nonmetals).

• Periodic Table Tip

  • Use the "staircase" on the periodic table to differentiate metals (left) from nonmetals (right).
  • Exception: Hydrogen is a non-metal despite its position.

Practice Examples

• Water (H₂O)

  • Composed of Hydrogen and Oxygen (both nonmetals) → Molecular compound.

• Copper (II) Fluoride

  • Copper (metal) and Fluoride (non-metal) → Ionic compound.

• Propanol

  • Composed of Carbon, Hydrogen, and Oxygen (all nonmetals) → Molecular compound.

• Lithium Nitrate & Sodium Sulfate

  • Contain metals and nonmetals → Ionic compounds.
  • Special type: Polyatomic ionic compounds.

Differences Between Ionic and Molecular Compounds

Bonding

• Molecular (Covalent) Compounds

  • Atoms share electrons to stick together.
  • Example: In water, Oxygen and Hydrogen are connected by shared electrons (like holding hands).

• Ionic Compounds

  • Electrons are transferred (stolen) from one atom to another, creating charges.
  • Example: In Sodium Chloride, Chlorine takes an electron from Sodium, forming positive (Sodium) and negative (Chlorine) ions that attract each other.

Structural Differences

• Molecular Compounds

  • Composed of molecules (clumps of atoms).
  • Example: Sugar molecules form clumps when they come together.

• Ionic Compounds

  • Form lattice structures (organized box-like shapes).
  • Example: Salt forms regular lattice structures.

Solubility

• Molecular Compounds dissolve into molecules.
• Ionic Compounds dissolve into individual ions.

Further Learning

• More information is available on the physical properties and solubility of ionic vs. molecular compounds in other videos.