What Is A Mixture?

Key Notes:

Definition of Mixture:

• A mixture is a combination of two or more substances that are physically combined.
• Each substance in a mixture retains its individual chemical properties.

Characteristics of Mixtures:

• The components can be separated by physical methods (e.g., filtration, distillation).
• No chemical change occurs when forming a mixture.
• The composition of a mixture is not fixed and can vary.

Types of Mixtures:

• Homogeneous Mixtures: The composition is uniform throughout (e.g., saltwater, air).
• Heterogeneous Mixtures: The composition is not uniform and components are visibly distinct (e.g., sand and iron filings).

Examples of Mixtures:

• Homogeneous: Sugar dissolved in water, vinegar.
• Heterogeneous: Oil and water, a bowl of cereal with milk.

Separation Techniques:

• Filtration: Separates solid particles from a liquid.
• Distillation: Separates components based on boiling points.
• Chromatography: Separates based on movement through a medium.
• Sieving: Separates particles of different sizes.

Importance of Mixtures in Daily Life:

• Used in food preparation (e.g., salad, juice).
• Industrial applications (e.g., alloys like steel).
• Medical uses (e.g., saline solution).

Comparison with Pure Substances:

• Pure Substances: Have a fixed composition and cannot be separated into simpler substances by physical methods.
• Mixtures: Have variable composition and can be separated physically.

Properties of Mixtures:

• Do not have a fixed melting or boiling point.
• Exhibit properties of their individual components.

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