Dilution refers to drop in the pH of a chemical which can be a gas, vapor or solution. It involves the process of decreasing the concentration of a solute in the solution normally by mixing with solvent. To dilute a solution add more solvent without the addition of more solute. Mix the resulting solution thoroughly to ensure that all parts of the solution are even.

For example, if 10 grams of salt is dissolved in 1 liter of water, it has a particular salt concentration. By adding 1 liter of water to this solution, the salt concentration is reduced. The dilute solution still has 10 grams of salt.

To prepare a fixed amount of dilute solution, we have a formula

C1V1 = C2V2

Where,

V1 denotes the Volume of stock solution needed to make the new solution

C1 = Concentration of stock solution

V2 is the final volume of the solution.

**Example 1**

A chemist needs 1.5M hydrochloric acid Â for a reaction. The solution available is 6M of HCl. What is the volume of 6M HCl to be diluted to obtain 5L of 1.5M HCl?

**Solution**

Initial concentration of HCl is 6M

Final concentration of HCl is 1.5M

Final volume of solution is 5L

The initial volume needs to be found.

Substituting the values, we get

Vi = 1.5 x 5.0 / 6

= 1.3 L

**Example 2**

If 500mL of 15% of X solution of methyl salicylate in alcohol is diluted to 1500mL, find the percentage of X.

**Solution**

Substituting the given values in the equation, we get

1500 / 500 = 15 / X

= 5%