Mixture
Definition
A mixture is a combination of two or more substances that are physically mixed but not chemically combined.
- Unlike compounds, mixtures do not participate in the process of chemical bonding.
- Substances held together by physical forces.
- Each item retains its properties in the mixture.
- Mixtures can exist in various forms: solutions, suspensions, or colloids.
Examples of Mixtures:
- Crude oil: A mixture of organic compounds (mainly hydrocarbons).
- Seawater: A mixture of various salts and water.
- Air: A mixture of gases like oxygen, carbon dioxide, nitrogen, and argon.
- Ink: A mixture of coloured dyes.
- Gunpowder: A mixture of sulphur, potassium nitrate, and carbon.
Type of Mixture
Homogeneous Mixtures: Homogeneous mixtures have a uniform composition. In these mixtures, the individual components are evenly distributed at the molecular level and cannot be visually distinguished.
- Example: saltwater (a solution of salt dissolved in water), air (a mixture of gases), and sugar dissolved in coffee.
Heterogeneous Mixtures: Heterogeneous mixtures have non-uniform compositions, with distinct regions containing different concentrations of the components.
- The individual substances in a heterogeneous mixture are typically visible to the naked eye and can be physically separated through methods such as filtration, decantation, or chromatography.
- Examples: sand and water, a salad containing various vegetables, and a mixture of oil and water.
In addition to being characterized as heterogeneous or homogeneous, mixture can also be described based on the particle size of the components:
- Solution: Solution contains very small particle sizes less than 1 nanometer in diameter. It is physically stable.
- Colloid: Colloid is a mixture of substances from 1 nanometer to 1 micrometer in diameter, dispersed in a solvent.
- Suspension: Are heterogeneous mixtures consisting particles that are visible to the naked eye. Substances will settle over time.
