Separating a precipitate, explaining properties of solutions/metals, hazard symbols and safety

🧪 1. Separating a Precipitate

🔹 What is a Precipitate?

  • A solid formed from a solution during a chemical reaction

Example:

  • Silver nitrate + sodium chloride → silver chloride (precipitate) + sodium nitrate

🔹 How to Separate a Precipitate

Step-by-Step:

  1. Filtration

    • Pour mixture through filter paper in a funnel

    • Solid stays on paper → precipitate

    • Liquid that passes through → filtrate

  2. Washing the Precipitate

    • Use distilled water to remove soluble impurities

  3. Drying

    • Leave on filter paper or in warm oven to remove water

💧 2. Properties of Solutions and Metals

🔹 Solutions

  • Solvent + solute

  • Properties:

    • Soluble → solute dissolves

    • Conductivity → depends on ions (ionic solutions conduct)

    • Saturation → max solute that can dissolve

🔹 Metals

  • General Properties:

    • Malleable (can be hammered)

    • Ductile (can be drawn into wire)

    • Good conductors of heat & electricity

    • High melting/boiling points

    • Solid at room temperature (except mercury)

🔹 Reactivity Trends

  • Metals react with:

    • Water → forms hydroxides + H₂

    • Acids → forms salt + H₂

  • More reactive metals → faster reactions

⚠ 3. Hazard Symbols and Safety

🔹 Common Hazard Symbols

Symbol

Meaning

Example

☣ Corrosive

Can burn skin/eyes

Concentrated acids/alkalis

☠ Toxic

Can poison if swallowed or inhaled

Cyanide

⚡ Oxidising

Provides oxygen to start fire

Hydrogen peroxide

🔥 Flammable

Catches fire easily

Ethanol

⚠ Irritant

Causes irritation

Some soaps, dilute acids

🧪 Harmful

Can cause mild effects

Some chemicals in lab

🔹 Lab Safety Rules

  • Wear safety goggles, lab coat, gloves

  • Use fume cupboard for harmful gases

  • Keep flammable chemicals away from flame

  • Wash hands after experiments

  • Label chemicals correctly

🔗 Big Links

  • Separating precipitates → practical skill, shows chemical reaction

  • Properties of solutions/metals → explain reactions & conductivity

  • Hazard symbols → ensure safe handling in experiments

⭐ Exam Tips

  • For filtration, always mention filter paper, funnel, wash, and dry

  • Metals: always mention conductivity and malleability

  • Solutions: mention ions and solubility

  • Hazard symbols: name + meaning + example