Kinetic Molecular Theory and Properties of Matter

Kinetic Molecular Theory (KMT)

• Gases have no intermolecular forces (IMFs), leading to low density, high compressibility, and diffusion.
• Liquids have moderate IMFs, higher density than gases, defined volume but no defined shape, and can diffuse.
• Solids have strong IMFs, high density, and defined volume and shape, with negligible compressibility and no diffusion.

Key Concepts of KMT

• Average kinetic energy varies among molecules even at the same temperature due to collisions and energy exchange.
• The average kinetic energy of solids equals that of liquids at the same temperature, but molecular movement differs.

Types of Bonds

Intramolecular Bonds:

• Ionic Bond: Transfer of electrons between highly and low electronegative (EN) atoms.
• Covalent Bond: Electrons shared between atoms with similar EN.
• Metallic Bond: Delocalized electrons moving among metallic nuclei.

Intermolecular Bonds (Listed by increasing strength):

1. London Dispersion Forces (between nonpolar molecules)
2. Ion-Induced Dipole/Dipole-Induced Dipole
3. Dipole-Dipole
4. Hydrogen Bonding (specific to water, HF, NH3)

Properties of Matter

• Solids:
  • High solubility, conductivity (due to electron/ion movement), malleability (nondirectional covalent bonds), and brittleness (like charges repel).
• Liquids: Have defined volume but no shape, and diffuse.
• Gases: No defined shape or volume, easily compressed, and can diffuse.

Solution Types and Properties

• Interstitial Alloys: Smaller atoms fit between larger metal atoms.
• Substitutional Alloys: One metal type replaces another of similar size.

Volatility and Properties Comparison

• Alcohol is more volatile than water due to weaker bonding (fewer hydrogen bonds).
• Water has high surface tension due to hydrogen bonding, resulting in low volatility and slow evaporation.