What is a Mixture?
A mixture is a substance containing two or more different chemical substances that are not chemically bonded together. Unlike compounds, mixtures can typically be separated by physical means and retain the properties of their individual components. They are broadly classified into two main types: homogeneous and heterogeneous.
Homogeneous Mixtures (Solutions)
A homogeneous mixture is a mixture in which the composition is uniform throughout, appearing as a single phase. The components are evenly distributed and cannot be distinguished from one another, even under a microscope. These mixtures are often called solutions, where a solute is dissolved in a solvent. Examples include salt water, air, and brass.
Heterogeneous Mixtures
A heterogeneous mixture is a mixture where the components are not uniformly distributed and can be visually identified, often existing in distinct phases. You can see the different parts of a heterogeneous mixture, and their properties can vary from one point to another within the mixture. Examples include sand and water, oil and vinegar, or a bowl of mixed nuts.
Key Distinctions and Examples
The primary difference lies in uniformity: homogeneous mixtures have a consistent composition and appearance (like sugar dissolved in water), while heterogeneous mixtures have visibly distinct components (like granite, where you can see different mineral grains). This distinction is crucial for understanding material properties and separation techniques in chemistry.