Separation of Mixtures
Since mixtures consist of two or more substances combined physically, they can be separated using physical methods. The choice of separation technique depends on the properties of the components, such as particle size, boiling point, solubility, and state of matter.
1. Filtration
Principle: Separation based on particle size.
Method: A filter paper or sieve is used to separate an insoluble solid from a liquid.
Example:
Separating sand from water.
Removing tea leaves from tea using a strainer.
2. Evaporation
Principle: Separation based on different boiling points.
Method: The liquid component of a mixture is heated until it evaporates, leaving behind the solid.
Example:
Obtaining salt from saltwater.
Drying wet clothes in the sun.
3. Distillation
Principle: Separation based on differences in boiling points.
Method: The mixture is heated, and the component with the lower boiling point evaporates first, is condensed, and collected separately.
Types:
Simple Distillation: Used to separate a liquid from a dissolved solid.
Fractional Distillation: Used to separate two or more liquids with close boiling points.
Example:Purifying water from seawater.
Separating alcohol from water.
4. Sublimation
Principle: Some solids directly change into gas without passing through the liquid state.
Method: The sublimable solid is heated, and its vapors are collected and cooled to form pure solid crystals.
Example:
Separating ammonium chloride from sand.
Separation of iodine and naphthalene.
5.
Principle: Separation based on differences in solubility and adsorption on a surface.
Method: A mixture is passed through a medium (like filter paper), and different components travel at different speeds.
Example:
Separating different colors in ink.
Identifying substances in drugs.
6. Centrifugation
Principle: Separation based on differences in density.
Method: The mixture is spun at high speed in a centrifuge, causing denser particles to settle at the bottom while lighter particles remain at the top.
Example:
Separating cream from milk.
Separating blood components in laboratories.