Exploring Mixtures and Their Separation Flashcards

Classification of Mixtures

  • Mixture: A combination of two or more substances not chemically combined.

  • Homogeneous Mixture: Composition is uniform throughout (e.g., Salt in water).

  • Heterogeneous Mixture: Composition is not uniform throughout (e.g., Water in oil, chalk powder in water).

Properties of Solutions, Suspensions, and Colloids

  • Solution: A homogeneous mixture with particles < 1\,nm. Particles are too small to scatter light or be seen by the naked eye and cannot be filtered.

  • Solid Solution (Alloy): Homogeneous mixtures of metals and non-metals that cannot be separated by physical methods (e.g., Bronze is an alloy of copper and tin).

  • Suspension: A heterogeneous mixture with visible particles that scatter light and can be separated by filtration.

  • Colloid: Appears homogeneous but is actually heterogeneous. Particles scatter a beam of light (Tyndall Effect) and are separated via centrifugation (e.g., Milk).

Concentration and Solubility

  • Mass by Mass Percentage: Mass of soluteMass of solution×100\frac{\text{Mass of solute}}{\text{Mass of solution}} \times 100

  • Mass by Volume Percentage: Mass of soluteVolume of solution×100\frac{\text{Mass of solute}}{\text{Volume of solution}} \times 100

  • Volume by Volume Percentage: Volume of soluteVolume of solution×100\frac{\text{Volume of solute}}{\text{Volume of solution}} \times 100

  • Saturated Solution: A solution where no more solute can be dissolved at a specific temperature.

  • Solubility: The max solute amount in 100 ml100\,ml or 100 g100\,g of solvent. Solubility of solids in liquids increases with temperature, while solubility of gases in liquids increases as temperature decreases.

Methods of Separation

  • Crystallisation: Cooling a saturated solution slowly to form pure solid crystals (e.g., Sugar crystals).

  • Distillation: Separating miscible liquids by boiling point differences (e.g., Acetone and water).

  • Paper Chromatography: Separating components based on solvent and stationary phase interactions (e.g., Ink pigments).

  • Separating Funnel: Separating immiscible liquids by densities (e.g., Mustard oil and water).

  • Sublimation: Separating a sublimable solid from a non-sublimable one (e.g., Camphor and sand).

  • Centrifugation: Spinning a mixture at high speeds to settle heavier particles (e.g., Cream from milk).

  • Coagulation: Adding a coagulant like Alum (fitkan) to clump fine particles in muddy water into larger masses (flocs).