pH is a very convenient scale to measure large variations of [H3O+] concentrations.
pH is defined
by the expression below
|The above expression can be rearranged to give:
|Example1. Calculate the pH of a 0.1M HCl solution.
Step 1 find the concentration of hydronium ions. Since HCl is a strong acid the reaction represented by the equation below has a very high Ka value therefore the reaction proceeds almost to completion.
|The concentration of HCl should be equal to the concentration of hydronium
|Example 2. Calculate
the concentration of hydronium ions in a sample of a lemon soda drink of pH 3.0.
Step 1 Apply the formula below