Notes on Separating Mixtures

Evaporation
- Definition: Process where a liquid changes to gas when heated. Used to separate a dissolved solid from a liquid.
- Mechanism: The liquid escapes as vapor, leaving the solid behind.
- Example: Salt left behind when seawater dries up.
Filtration
- Definition: Separates an insoluble solid from a liquid using a filter.
- Mechanism: The liquid + dissolved substances pass through as filtrate, while the solid stays as residue.
- Example: Sand from water.
Crystallisation
- Definition: Forms pure solid crystals from a solution.
- Procedure: Solution is heated to evaporate some solvent, then cooled slowly so the dissolved solid forms crystals.
- Key Advantage: Gives purer solid than evaporation alone.
- Example: Making copper sulfate crystals from solution.
Chromatography
- Definition: Separates components of a mixture based on how fast they move through a material.
- Mechanism: Components travel different distances due to different solubilities/attraction to the stationary phase.
- Example: Separating dyes in ink on paper with water.

Filtration
- Water Treatment: Removes dirt, sand, and debris from drinking water.
- Daily Life: Coffee filters, air filters in AC, and vacuum cleaners trap particles.
Chromatography
- Forensics: Identifies substances in blood, detects drugs or poisons.
- Food Safety: Checks for additives, contaminants, or food coloring purity.

Separation Procedure for Salt + Sand + Water + Ink Mixture
- Step 1: Filtration
- Procedure: Pour mixture through filter paper.
- Residue: Sand stays as residue.
- Filtrate: Saltwater + ink pass through as filtrate.