Question

Why $\mathrm{HCl}$ is not used in titration?

Answer 1

$\mathrm{HCl}$:

1. At normal temperature and pressure, hydrogen chloride $\mathrm{HCl}$ is a gas made up of the elements hydrogen and chlorine.
2. Hydrochloric acid is the name for a gas solution in water.

Reason for $\mathrm{HCl}$ is not used in titration:

1. Typically, we add $\mathrm{HCl}$ to the ${\mathrm{KMnO}}_4$ solution to make it acidic. However, the $\mathrm{HCl}$ is oxidized when a few drops of $\mathrm{HCl}$ are added to the potassium permanganate solution.
2. This is due to ${\mathrm{KMnO}}_4$'s potent oxidizing properties. It produces chlorine gas by oxidizing the $\mathrm{HCl}$. The medium does not turn acidic as a result. However, an acidic medium is required for titration.
3. As a result, we rarely add weak acid during titration. When $\mathrm{HCl}$ is introduced to a ${\mathrm{KMnO}}_4$ solution, the following reaction occurs: $2{\mathrm{KMnO}}_4+16\mathrm{HCl}\to 2\mathrm{KCl}+2{\mathrm{MnCl}}_2$
4. ${\mathrm{H}}_2{\mathrm{SO}}_4$ is preferred over $\mathrm{HCl}$ in this case. This is so that the solution is more acidic than $\mathrm{HCl}$ due to the significant acidity of ${\mathrm{H}}_2{\mathrm{SO}}_4$. Therefore, when we utilize ${\mathrm{H}}_2{\mathrm{SO}}_4$ in titration, the final results are more accurate.
5. While $\mathrm{HCl}$ only produces one hydronium ion, ${\mathrm{H}}_2{\mathrm{SO}}_4$ produces two. ${\mathrm{HNO}}_3$ is another alternative to $\mathrm{HCl}$. Also excluded from the titration procedure is ${\mathrm{HNO}}_3$. Mineral acids are another name for $\mathrm{HCl}$ and ${\mathrm{HNO}}_3$.