- **Same solute**: In the mixture of solutions of the same solute, there is no chemical reaction between these solutions. In this case, the final volume value is the sum of the solutions.

Where:

C = common concentration (g / L)

M = molarity (mol / L)

V = volume (L)

Example:

What is the molarity of a NaOH solution formed by mixing 60mL of 5mol / L solution with 300mL of 2mol / L solution?

- **Of different solutes that react with each other**: reaction occurs between the substances that make up the mixture. For the reaction to be complete between the solutes, the mixed volumes must obey the stoichiometric proportion that corresponds to the chemical reaction. See the formulas used:

Neutralization Reaction:

You can use the following formula:

Where:

x_{The} = number of H +

x_{B}= number of OH-

These calculations can also be done by rule of three and using the other formulas. Example:

By combining 300mL of 0.4mol / L HCl with 200mL of 0.6mol / L NaOH, one wonders what will be the molarities of the final solution with respect to:

a) acid:

b) at the base:

c) the salt formed:

Mount the chemical reaction:

Calculate n (mol number) of acid and base:

If 0.12 moles of acid and base are formed and the stoichiometric ratio is 1: 1, then the final molarity of acid and base is **zero**, because the whole solute reacted.

To calculate the molarity of salt (before finding the final volume):