Solution and solubility

• When we add some salt to water and stir it, the salt disappears.
• This is because the salt has dissolved in water.
• Dissolving is a change where substances mix completely with the liquid they have been added to and cannot be separated easily.
• All substances do not dissolve in water.

Solute:

• The component of a solution which is present in lesser amount is called the solute.

OR

• The component of a solution which is added to the solvent is called the solute.

Solvent:

• The component of a solution which is present in more amounts is called the solvent.

OR

• The component of a solution in which solute is added is called the solvent.

Solution:

• The homogenous mixture of two or more substances is called the solution.
• Thus, solute + solvent = solution

e.g., sugar + water = sugar solution

• If sugar is added to water with stirring, it dissolves and if we keep on adding sugar to the solution , after some time we will notice that some grains of sugar settle at the bottom of the solution.
• This shows that no more sugar can be dissolved. We say that the solution has become saturated.
• A saturated solution is the solution in which no more of the solute can be dissolved.

Solubility:

• The ability of a substance to get dissolved in a given liquid is called solubility.
• The solubility of a substance can be increased by heating the solution.

Example:

• The quantity of sugar that can be dissolved in hot water is much more as compared to that in cold water.

• There are some other factors that increase the solubility of a solute.

1. Stirring:

1. We can observe this by taking two glasses of water and adding a teaspoonful of sugar to each glass.
2. Keep one glass undisturbed and stir the other.
3. Sugar dissolves faster in the glass in which the solution is stirred.

2. Solute in powdered form:

• Solute in powdered form dissolves faster than the solute present in solid form.

Example:

• Crushed sugar dissolves faster in water than sugar cube.