Notes 2. Is Matter around us Pure - Types of mixtures and solution | Class 9 Science - Toppers Study

2. Is Matter around us Pure?

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Types of Mixtures:

(I) Homogeneous: The mixture which has uniform compositions and its compositions can not be identified seperatly is known as homogeneous mixture. 

Example: Solution of water and salt. 

(ii) Hetrogeneous: The mixtures which contain physically distinct parts and have non-uniform compositions, such mixtures are called hetrogeneous mixtures. 

Examples: sand and salt, sugar and salt, water in oil etc. 

Properties of mixtures:

(i) The components of mixtutes can easily be seperated. 

(ii) Each component has its own charectristics. 

(iii) Components are distinct in ratio. 

Solution: 

A solution is a homogeneous mixture of two or more substances.

Example: Lemon water, soda water etc. 

Solution are found in three states of substances.

(1) Solid solution: Alloys.

(2) Liquid solution: Lemon water.

(3) Gaseous solution: Air. 

• There is homogeneity at the particle level in the solution so that its particles can not be identified in distinct manner. 

Properties of solutions: 

(i) It is a homogeneous mixture. 

(ii) It has homogeneity at particle level therefore its particles can not be seen by necked eyes. 

(iii) The path light can not be seen in solution.

(iv) Solution is stable. 

(v) The solute particles cannot be separated from the mixture by the process of filtration.

Components of Solution:

(1) Solvent: The component of the solution that dissolves the other component in it and it is usually present in larger amount, such component of solution is called the solvent.

Examples of solvents: water, alcohal,  tarpentine oil etc. 

(2) Solute: The component of the solution that is dissolved in the solvent and it is usually present in lesser quantity, such component is called the solute.

Examples of solutes: salt, sugar, soda, potassium permagnete and iodine etc. 

Solubility: The amount of the solute present in the saturated solution at this temperature is called its solubility. 

condition that affect solubility:

(i) Temperature

(ii) Pressure

(iii) Nature of solute and solvent

Concentration: Concentration is special quantity of a substance presents in per unit volume in a mixture. 

In other words: 

The quantity of a substance present in a mixture is called concentration of that substance. 

Concentration of a solution: 

The amount of solute present in a given amount
(mass or volume) of solution, or the amount of solute dissolved in a given mass or volume of solvent is called the concentration of a solution.

Methods to find concentration of a solution:

There are various ways of expressing the concentration of a solution, but here we will learn only two methods.

Two common methods to find concentration of a solution.

(i) Mass by mass percentage of a solution

          

(ii) Mass by volume percentage of a solution

         

Types of solutions: 

(1) Saturated solution: At any particular temperature, a solution that has dissolved as much solute as it is capable of dissolving, is said to be a saturated solution.

In other words,

When no more solute can be dissolved in a solution at a given temperature, it is called a saturated solution.

(2) Unsaturated solution: If the amount of solute contained in a solution is less than the saturation level, it is called an unsaturated solution.

(3) High/super saturated solution: If the amount of solute contained in a solution is more than the saturated level, such a solution is called high-saturated solution.