Mixtures

Mixture is a collection formed by the combination of different types of atoms and molecules. substance substances consist either of a single element or a single compound, but most but substances are neither a single element nor a single compound. Many objects we encounter in daily life are not pure and belong to the category of mixtures. For example, the air we breathe, the food we eat chocolate, and the milk we drink are all examples of mixtures.

General Properties of Mixtures

1. The chemical properties of the substances forming the mixture do not change. An example is saltwater. In this mixture, neither water nor salt loses its identity.
2. The melting and boiling points are not fixed.
3. The densities of mixtures are not constant. The density of the mixture varies depending on the amounts of the substances that compose it.
4. Since mixtures are composed of substances that combine through physical means, the components are separated using physical methods. The method chosen depends on differences in properties such as particle size, density, solubility, electrification, magnetic properties, melting point, and boiling point.
5. There is no fixed ratio between the amounts of substances forming the mixture.
6. The formation of mixtures results in the appearance of various phases. A phase is a region in which the physical properties of a material are uniform throughout. If a mixture exhibits only one phase, it is called homogeneous; if it exhibits more than one phase, it is called heterogeneous.

Homogeneous Mixtures

The components are evenly distributed throughout. They consist of a single phase. These types of mixtures are also called solutions. They can arise from solid-solid, liquid-gas, and gas-gas like interactions.

Heterogeneous Mixtures

Heterogeneous mixtures are those in which the composition is not uniform throughout, the components are not evenly distributed, and the substances do not dissolve in one another. They consist of multiple phases. Examples include sandy water, ink, fog, chalk-dust in water, and oil-in-water mixtures. When one substance in the mixture is dispersed within another, the dispersed substance is called the dispersed phase and the substance in which it is dispersed is called the dispersion phase. Heterogeneous mixtures are classified according to the physical states of the dispersion and dispersed phases:

Emulsion

Mixtures in which both the dispersion and dispersed phases are liquids are called emulsions. Examples include water-oil mixtures, water-diesel mixtures, milk, and mayonnaise.

Suspension

Mixtures in which the dispersion phase is liquid and the dispersed phase is solid are called suspensions. Examples include chalk in iodine water, muddy water, sand-water, and ayran mixtures. In these mixtures, the solid phase settles over time due to the effect of duration place.

Aerosol

Heterogeneous mixtures in which the dispersion phase is gas and the dispersed phase is solid or liquid are called aerosols. If the dispersed phase is solid, it is called a solid aerosol; if it is liquid, it is called a liquid aerosol. Fog, spray, insect sprays, deodorants, and cloud are liquid aerosols. Smoke and dusty air are solid aerosols.

Ordinary Mixture

These are solid-solid heterogeneous mixtures. In ordinary (simple) mixtures, it is not possible to distinguish between the dispersed and dispersion phases. Examples include sand-sugar, salt-sugar, rice-bulgur, soil, and nut mixtures.

Colloid

Colloids are mixtures in which a solid or liquid is suspended in a liquid or gas, appearing homogeneous but actually heterogeneous. This can be determined by observing that when a beam of light is passed through them, the light is scattered in all directions, or by microscopic examination, since homogeneous mixtures do not scatter light. The majority of emulsions and aerosols are also colloids. Examples include milk, smoke, mayonnaise, cream, jelly, soapy water, and blood.