Lecture Notes: Matter and Its Properties

Introduction

• Matter: Anything with mass and volume; has the property of inertia.
• Objectives:
  • Differentiate between elements, compounds, and mixtures.
  • Understand properties of solutions.
  • Differentiate between suspension and colloidal solution.
  • Learn about separation of miscible and immiscible liquids.
  • Understand separation of air components.

Classification of Matter

Substances

• Definition: Material with constant composition (e.g., NaCl, H2O, CO2, O2).
• Characteristics: Same composition everywhere, includes all elements and compounds.

Elements

• Definition: Made up of one type of atom; 113 known elements.
• Properties: Can't be broken down by chemical means.

Compounds

• Definition: Substances with more than one type of atom (e.g., water, CO2, table salt).
• Characteristics: Chemically combined, can be decomposed by chemical reactions.

Phases

• Definition: Regions of a material with unique properties.
• Examples: Pure gold (one phase), chocolate chip cookie (multiple phases).

Homogeneous and Heterogeneous Materials

Homogeneous Materials

• Definition: Contain one phase, uniform throughout (e.g., hydrogen, sugar, salt water).

Mixtures

• Definition: Two or more physically combined substances.
• Types:
  • Homogeneous mixtures: Well-blended, uniform (e.g., solutions).
  • Heterogeneous mixtures: More than one phase, not uniform (e.g., salad, sand).

Solutions

• Definition: Homogeneous mixture; parts physically combined (e.g., iced tea, air).
• Components:
  • Solute: Dissolved substance.
  • Solvent: Dissolving medium.
• Examples: Salt water, sugar solution.

Heterogeneous Mixtures

• Characteristics: More than one phase, can be separated physically.

Differences Between Elements, Compounds, and Mixtures

• Elements: Simple substances, cannot be broken down.
• Compounds: Chemical combination of elements, can be broken down.
• Mixtures: Physical combination, retain individual properties.

Types of Solutions

• Unsaturated: More solute can be dissolved.
• Saturated: Maximum solute dissolved.
• Supersaturated: More solute than saturation point.

Properties of Solutions

• True Solution: Homogeneous, clear, solute particles not visible.
• Suspensions: Heterogeneous, particles visible, can be filtered.
• Colloids: Between solution and suspension, Tyndall effect visible.

Separation Techniques

• Heterogeneous Mixtures: Separated by physical methods.
• Immiscible Liquids: Using separating funnel.
• Miscible Liquids: By distillation.

Special Processes

• Sublimation: Solid to gas directly (e.g., iodine).
• Crystallization: Formation of pure substance crystals.

Physical vs. Chemical Changes

• Physical Change: Changes in state without chemical change.
• Chemical Change: Alters chemical nature, results in new substances.

Summary

• Matter: Elements, compounds, mixtures.
• Solutions: Homogeneous dispersions.
• Suspensions & Colloids: Mixture types based on particle size and behavior.