Mind Map :: Chapter 2: Is matter around us pure

Common Perspective: "Pure" means no adulteration (e.g., milk, ghee).

Scientific Perspective: A pure substance consists of a single type of particle (e.g., sodium chloride, sugar).

Definition: Combination of two or more pure substances.

Characteristics:

1. Components can be separated by physical processes (e.g., evaporation).

2. Examples: Milk (water, fat, proteins), seawater, soil.

Types:

1. Homogeneous Mixtures: Uniform composition (e.g., salt in water).

2. Heterogeneous Mixtures: Non-uniform composition (e.g., oil and water).

Definition: Homogeneous mixture of two or more substances.

Components:

1. Solvent: Dissolves the solute (e.g., water in sugar solution).

2. Solute: Dissolved in the solvent (e.g., sugar in sugar solution).

Properties:

1. Particles are evenly distributed.

2. Particles are less than 1 nm in size.

3. Do not scatter light (no Tyndall effect).

Examples:

1. Solid in liquid: Sugar in water.

2. Gas in liquid: Carbon dioxide in soda water.

3. Gas in gas: Air (oxygen, nitrogen).

Definition: Mixture of two or more metals or a metal and non-metal.

Properties:

1. Retain properties of constituents.

2. Cannot be separated by physical methods.

Example: Brass (zinc and copper).

Definition: The amount of solute dissolved in a given quantity of solvent.

Types:

1. **Dilute Solution:** Small amount of solute in solvent.

2. **Concentrated Solution:** Large amount of solute in solvent.

Formulas:

Mass by Mass % = $\frac{\mathrm{Mass\; of\; Solute}}{\mathrm{Mass\; of\; Solution}}\times \; 100$

Mass by Volume % = $\frac{\mathrm{Mass\; of\; Solute}}{\mathrm{Volume\; of\; Solution}}\times \; 100$

Volume by Volume % = $\frac{\mathrm{Volume\; of\; Solute}}{\mathrm{Volume\; of\; Solution}}\times \; 100$

Definition: Heterogeneous mixture with visible particles that settle over time.

Properties:

1. Particles scatter light (Tyndall effect).

2. Unstable; particles settle on standing.

3. Can be separated by filtration.

Example: Muddy water.

Definition: Heterogeneous mixture with particles too small to be seen but large enough to scatter light.

Properties:

1. Particles do not settle.

2. Scatter light (Tyndall effect).

3. Cannot be separated by filtration but can be separated by centrifugation.

Examples: Milk, fog, smoke.

Evaporation: Separates volatile components (e.g., water from ink).

Separating Funnel: Separates immiscible liquids (e.g., oil and water).

Sublimation: Separates sublimable substances (e.g., camphor from salt).

Chromatography: Separates components based on solubility (e.g., dye separation).

Distillation: Separates miscible liquids based on boiling points (e.g., acetone and water).

Crystallization: Purifies solids from solutions (e.g., copper sulfate).

Physical Change: No change in chemical composition (e.g., melting ice).

Chemical Change: Formation of new substances (e.g., burning wood).

Elements: Cannot be broken down into simpler substances (e.g., gold, oxygen).

Compounds: Formed by chemical combination of elements in fixed proportions (e.g., water, salt).

Metals: Shiny, conductive, malleable (e.g., iron, copper).

Non-Metals: Poor conductors, various colors (e.g., carbon, oxygen).

Metalloids: Properties intermediate between metals and non-metals (e.g., silicon).

Formation: Through chemical reactions (e.g., iron + sulfur → iron sulfide).

Properties: Different from constituent elements.

Separation: Requires chemical methods.