A mixture is a material made up of two or more different substances which are mixed but are not combined chemically They can be separated from each other without a chemical reaction, in the way that different colored sweets can be picked out from a mixed packet and put into separate piles. Those substances may also be referred to as constituents or components and may be either elements or compounds, and be composed of either atoms or molecules. A mixture refers to the physical combination of two or more substances in which the identities are retained and are mixed in the form of solutions, suspensions, and colloids. Some examples of mixtures are a tossed salad, salt water and a mixed bag of M&M’s candy.
Methods of separating mixtures:
- Filtration: Separation by particle size. The particle size of substances can be very different. Passing a mixture through a screen or filter will allow the small particles to pass and be separated from the larger particles that get trapped.
- Distillation: Separation by boiling point differences. Typically a mixture is heated gradually and the substances that vaporize the easiest will separate first.
- Floatation: Separation of solids by density different, when put into water, some substances will sink while others will float. The floaters can then be skimmed off the surface.
- Magnetism: Some substances are attracted to a magnet field and can be pulled from a mixture.
- Crystallization: Separation by solubility. Substances have different solubilities at temperatures. A solution can be cooled to the point where the solute will begin to form crystals and separate from the mixture.
Why separate mixtures?
Mixtures are separated to get the components present in it differently. To separate the mixtures is very important as to separate the useful components of the mixture to separate the impurities from the components and to separate the non-useful substances from the useful ones such as churning of milk to separate butter, separation of wheat bran from flour.
The process of separation:
Separation differs in chemical properties or physical properties such as size, shape, mass, density or chemical affinity between the constituents of a mixture. A separation process is a method to achieve any happening that converts a mixture of a chemical substance into two or more defined product mixture. The separation divides the mixtures into pure constituents. They are classified according to the particular differences they use to achieve separation. If no single difference is used to achieve the desired separation then multiple operations will be performed in combination to get the desired end.
An everyday example of the mixture in our daily life:
- Saltwater: Salt is the mixture because the salt and water that are mixed to give salt water can both be separated. Even if the salt is completely mixed with the water it can be separated by boiling the salt water.
- Sugar water: When the sugar and water are mixed and stirred together it removes the boiling mixture of sugar water. The water can be collected through the process of condensation, where the salt will be left over once the water has been boiled.
- Salad: The common everyday mixture we see. Every salad contains tomatoes, cucumber, lettuce and other ingredients according to the personal choice and any ingredient can be easily removed if a person doesn’t want it.