Chapter 9, Problem 60P

Interpretation Introduction

Interpretation:

Comprehend the true statement about the determination of acidic nature of solution with the help of pH of solutions.

Concept Introduction:

A substance is said to be acidic if it can give hydrogen ions ( ${\text{H}}^{\text{+}}$ ) whereas a base is said to be a substance that can give ${\text{OH}}^{\text{-}}$ ion. This theory of acid and base is called the Arrhenius theory of acid and base.

Another theory that is purposed by Bronsted and Lowery is called Bronsted-Lowry acid-base theory. It states that acid can give ${\text{H}}^{\text{+}}$ ions whereas a base can accept the ${\text{H}}^{\text{+}}$ ion in its solution. Hence this theory is entirely based on the presence of ${\text{H}}^{\text{+}}$ ion in the given substance.

The acidic and basic nature of the solution can be expressed in terms of pH of the solution. The range of pH lies from 0 to 14. The pH value from 0 to 7 indicates an acidic solution whereas the pH value from 7 to 14 stands for a basic solution. A neutral solution can be expressed as pH 7. It can be calculated with the help of concentration ${\text{H}}_{\text{3}}{\text{O}}^{\text{+}}$ ions and can be formulated as:

  ${\text{pH = - log [H}}_{\text{3}}{\text{O}}^{\text{+}}\text{]}$