Large amount of salt is dissolved in seawater. This makes it unfit for drinking directly. Can we say that the amount of salt in the sea is the same everywhere?
The air contains gases like oxygen, carbon dioxide and ozone along with various small particles like pollen grains and dust. Are the gases and the particles present in equal amounts in air?
Soil contains a lot of substances, e.g., clay, organic matter, minerals, pebbles, etc.
Why do the amounts of clay, organic matter, minerals, etc. in soil vary from place to place?
All of the above substances (soil, air and seawater) are examples of mixtures. Let us go through the lesson to find out what mixtures are.
A mixture may be defined as a material having two or more types of pure forms of matter. For example, milk is a mixture as it contains a combination of water molecules, fat molecules and protein molecules. The constituents of a mixture can be separated by certain physical processes such as evaporation and boiling. Constituents of certain mixtures can also be separated manually. For example, a mixture of stones and sand can be separated manually. On the other hand, salt cannot be manually separated from saltwater. One needs to boil the mixture to separate the salt from water.
Now that we know what mixtures are, let us study about solutions. Whenever we talk about solutions, we instantly think of liquids. But is it necessary for all solutions to be liquids?
No. A solution is simply a homogeneous mixture of two or more substances. Solutions can be solid, liquid and gaseous. [[mn:glossary]]Alloy[[/mn:glossary]] is an example of a solid solution, while air is a gaseous solution.
A mixture is called solution when it has homogeneity at the particle level. A solution is formed when a [[mn:glossary]]solute[[/mn:glossary]] is dissolved in a [[mn:glossary]]solvent[[/mn:glossary]].
Examples of solutions
2. Solution of iodine in alcohol
4. Soda water
Nitrogen (present in the largest amount)
Other gases (present in relatively smaller amounts)
Properties of Solutions
- They are homogeneous mixtures of solutes and solvents.
- The solute particles in a solution are extremely small in size. They are less than 1 nm (10−9 m) in diameter.
- The solute particles are not visible to the naked eye.
- As a result of the small size of the solute particles, a solution does not scatter a beam of light passing through it.
- Being small in size, the solute particles get dissolved in t...
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