Question

How does pH relate to concentration?

Answer 1

We can define pH as the power of hydrogen (or) potential of hydrogen. It is used to specify the basicity (or) acidity of an aqueous solution. We can say that the pH scale is logarithmic and contrarily demonstrates the concentration of hydrogen ions in the solution.

Complete step by step answer:
We can say that the pH scale is logarithmic and contrarily demonstrates the concentration of hydrogen ions in the solution. This is because the expression used to determine the pH approximates the negative of the base 10 logarithm of the molar concentration of ions of hydrogen in the solution. pH is the negative of the base 10 logarithm of the hydrogen ion activity.
The acidity (or) basic nature of a solution could be determined using the pH. In a common way, the pH of acidic solution would lower as the concentration of solution is more. When it comes to bases, the pH will be more for more concentrated solutions. We can give the relation between the concentration of hydrogen ion and pH as,
$pH = - log\left[ {{H^ + }} \right]$
From the relationship, we can determine that if the pH of the solution is less, then the concentration of hydrogen ion would be higher.
In case if the pH of the solution is low, and the concentration of hydrogen ion is more in the solution, then we call such solutions acidic solutions. If the pH of the solution is more, and the concentration of hydrogen ion, then we call such a solution a basic solution.
So, we can conclude that the pH of the solution is inversely associated with the concentration of hydrogen ion in the solution.

Note:
We can say that pOH is used to determine the concentration of hydroxide ions present in the solution. We can obtain the values of pOH from the measurements of pH. We can calculate the pOH of the solution from the pH using the expression,
$pOH = 14 - pH$
We can use pH indicators to measure pH. The indicators change the color with respective to pH. From the color changes, we can determine the nature of the solution.