Atoms, Elements And Compounds – Session 2

As we know, a mixture is formed when two or more than two components are mixed together. These components can be elements or compounds. The mixtures can be classified into two types. These are homogeneous mixtures and heterogeneous mixtures.

In a homogeneous mixture, the components are uniformly distributed throughout the mixture. Every part of a homogeneous mixture is the same as every other part. For example, a mixture of salt and water is a homogeneous mixture. When you mix salt in water, both components are evenly and thoroughly mixed at the molecular level.

Another example of a homogeneous mixture is the sugar dissolved in water. Sugar solution do not have visible boundaries. This means that if you take a sample from one part of a mixture or another part of it, it will have the same composition. A homogeneous mixture is also called a solution.

Air is also a homogeneous mixture of different gases. Different gases are there in air. These gases include nitrogen gas, carbon dioxide gas and oxygen gas. These gases are uniformly mixed into each other.

When we breathe-in air, we take in all the gases in our lungs. This means the homogenous mixture of oxygen, carbon dioxide, nitrogen and other gases goes into our lungs.However, we only need oxygen gas to live. That is why we only use oxygen gas out of the air. Other gases are exhaled out when we breathe out.

As we have studied, a homogeneous mixture of two or more than two substances is called a solution. Let us discuss about the components of the solution.A solution is made of two components. One component is called the solute. The other component is called the solvent.

The substance that gets dissolved is called the solute. Let us say you dissolve sugar in water. Sugar is the solute. This is because sugar gets dissolved in the water.

The substance that does the dissolving is called the solvent. Or we can say that the substance that dissolves the solute is called the solvent.Suppose you dissolve the salt in water. The salt is the solute as it gets dissolved in water. The water is the solvent. This is because it dissolves the solute.

There are different types of solutions based on the state of the solute and the solvent. One type is called the solid in liquid solution. In this type of solution, a solid solute is dissolved in a liquid solvent. Sugar dissolved in water is an example of the solid in liquid solution.

Second type of solution is called the liquid in liquid solution. In this type of solution, the liquid solute dissolves in another liquid solvent.The solution of ethanol in water is an example of the liquid in liquid solution. The ethanol acts as the liquid solute. The water acts as the solvent.

The solute is always in less quantity as compared to the solvent in the solution. For example, in the ethanol in water solution, the ethanol is the solute and the water is the solvent. Can you tell what is the solute in water in ethanol solution. Here, the water acts as the solute in the water in ethanol solution.

Another type of solution is the gas in liquid solution. In this case, the gas solute is dissolved in the liquid solvent. You might have observed the gas coming out when you open a soda can. This gas is usually the carbon dioxide gas. It is dissolved in the liquid soda. So, soda is an example of the gas in liquid solution.

You might know about a gas in gas solution. Can you give any example of the gas in gas solution?.The air we breathe is an example of a gas in gas solution. This is because the air is the homogeneous mixture of different gases.

Heterogeneous mixtures are mixtures in which the components are not uniformly distributed throughout the mixture. The heterogeneous mixtures have visible boundaries between the different components. An example of a heterogeneous mixture is sand dissolved in water. The sand particles do not dissolve thoroughly in water.