One solution turns blue. A possible hydrogen ion concentration for this solution is: 1 * 10-2 M 5 * 10-2 M 5 * 10-4 M 1 * 10-8 M

1*10^-8 M

Explanation:

Since the solution turns blue, it means the solution is a base. Now, we shall determine the pH to know the possible hydrogen ion concentration for this solution.

1. pH = - log H+

H + = 1*10¯² M

pH = - log 1*10¯²

pH = 2

2. pH = - log H+

H + = 5*10¯² M

pH = - log 5*10¯²

pH = 1.3

3. pH = - log H+

H + = 5*10¯⁴ M

pH = - log 5*10¯⁴

pH = 3.3

4. pH = - log H+

H + = 1*10^-8 M

pH = - log 1*10^-8

pH = 8

A pH reading between 0 and 6 indicates an acid solution. A pH reading of 7 indicates a neutral solution. A pH reading between 8 and 14 indicates an alkaline/basic solution.

From the above calculations, we can see that the solution gives a pH of 8 indicating a basic solution when the hydrogen ion concentration is 1*10^-8 M