Mixtures and Separation of Mixtures

Mixtures

• A mixture is a combination of two or more pure substances, where each pure substance retains its individual chemical properties.
• Mixtures can be classified into heterogeneous and homogeneous mixtures.

Types of Mixtures

• Heterogeneous mixture: a mixture that does not blend smoothly throughout and in which the individual substances remain distinct.
• Homogeneous mixture: a mixture that has constant composition throughout and has a single phase.

Suspensions and Colloids

• Suspension: a mixture containing particles that settle out if left undisturbed.
• Colloid: a heterogeneous mixture with particles between 1nm to 1000nm in diameter that do not settle out.
• Brownian motion: the random movement of liquid colloid particles.
• Tyndall effect: the scattering of light due to the dispersed colloid particles.

Solutions

• Solution: a homogeneous mixture from two or more substances.

Separation of Mixtures

• Separation processes are based on the differences in the physical properties of the substances.
• Filtration: a technique that uses a porous barrier to separate a solid from a liquid.
• Distillation: a physical separation technique based on the differences in the boiling points of the substances involved.
• Crystallization: a separation technique that results in the formation of pure solid particles of a substance from a solution containing the dissolved substance.