# How do you do titration problems to find molarity?

Aug 7, 2016

See below.

#### Explanation:

Titration is used to determine the unknown molarity ($M$) of a solution (called analyte) using a titrant, which is a solution of known concentration.

Considering the analyte is an acidic solution (unknown molarity) and that it will be titrated using a basic solution with a known molarity (assuming monoprotic acid and base).

At the equivalence point, the number of mole of ${H}^{+}$ ions will be equal to the number of mole of $O {H}^{-}$ ions:

${n}_{{H}^{+}} = {n}_{O {H}^{-}}$

Note that the relationship between molarity and number of mole is:

$M = \frac{n}{V}$ where $V$ is the volume of the solution.

Thus, $n = M \times V$.

Therefore, ${M}_{a} \times {V}_{a} = {M}_{b} \times {V}_{b}$

$\implies {M}_{a} = \frac{{M}_{b} \times {V}_{b}}{{V}_{a}}$

Here is a video that fully explains this topic:
Lab Demonstration | Acid - Base Titration.