Differences between Compound and Mixture

Differences between Compound and Mixture

In chemistry, a compound is a substance formed when two or more chemical elements are chemically bonded together, whereas a mixture consists of two or more substances that are not chemically combined. Chemical reactions result in the formation of compounds. Conversely, mixtures are formed by physically combining substances.

Compounds are considered pure substances, while mixtures are classified as impure substances. The elements within a compound are present in a fixed ratio by mass, which is represented by a chemical formula. For example, water (H₂O) is a compound composed of hydrogen and oxygen atoms chemically combined in a 2:1 ratio. Mixtures, on the other hand, have variable ratios of their components. For instance, a saltwater solution can have different concentrations of salt.

The properties of a compound are distinct from those of its constituent elements. For example, sodium, a reactive metal, and chlorine, a toxic gas, combine to form sodium chloride (table salt), an essential compound for life. In a mixture, the individual components retain their original properties.

The formation of a compound involves a chemical change accompanied by an energy change, such as the release or absorption of heat or light. The creation of a mixture is a physical change with no associated energy change. Separating the components of a compound requires chemical methods to break the chemical bonds, such as electrolysis. In contrast, the components of a mixture can be separated by physical means.

Comparison Table

Category	Compound	Mixture
Formation	Chemical combination of elements in a fixed ratio.	Physical combination of substances in a variable ratio.
Chemical Bonds	New chemical bonds are formed.	No new chemical bonds are formed.
Properties	Has properties different from its constituent elements.	Components retain their individual properties.
Separation	Components can only be separated by chemical reactions.	Components can be separated by physical methods (e.g., filtration, evaporation).
Energy Change	Energy is either absorbed or released during formation.	No energy change occurs during formation.
Composition	Always homogeneous in nature.	Can be either homogeneous or heterogeneous.
Melting & Boiling Points	Has a fixed melting and boiling point.	Melts and boils over a range of temperatures.

Venn diagram comparing Differences between Compound and Mixture

Separation of Mixtures

The components of mixtures can be separated based on their physical properties. Common separation techniques include:

• Filtration: This method is used to separate an insoluble solid from a liquid, such as sand from water.
• Evaporation: This technique separates a soluble solid from a solvent by heating the solution until the solvent evaporates, leaving the solid behind.
• Distillation: This process separates liquids with different boiling points. The mixture is heated, and the liquid with the lower boiling point vaporizes first, is then condensed, and collected separately.
• Chromatography: This method is used to separate different components of a solution by passing it through a medium where the components move at different rates.