Question

Explain why diluting an acid raises the pH, but diluting a base lowers the pH.

Answer 1

A diluted acid solution will have a higher pH than the undiluted solution because the concentration of hydronium ion decreases upon dilution. Similarly, a diluted base solution will have a lower pH than the undiluted solution because the concentration of hydroxyl ion decreases upon dilution.

Answer 2

Dilution is the process of lowering concentration in a solution by including water or any other solvent.

As is well known, the basic solution has a higher concentration of hydroxide ions and an acidic solution has a higher concentration of hydrogen ions. Water causes an acidic or basic solution to change in pH.

The concentration of hydrogen ions decreases when water or another solvent is added to an acid. Due to this, the acid's pH rises to around 7. In other words, the ph rises as the acid solution is diluted.

A highly concentrated acid has a pH of about 1, but as we add water or any other solvent, the pH rises to about 7. The pH changes to 7 when it is extremely diluted and only a trace amount of acid is present.

It should be noted that dilution is the process of lowering a solute's concentration in a solution. To achieve this, we must increase the solvent without increasing the solute.

A solution is deemed acidic if the pH value is less than 7.

A solution is deemed to be basic if the pH value is greater than 7.

A solution is deemed neutral if the pH value is 7 or greater.