Final answer:
To calculate the volume of 0.885 M KOH needed for a solution with pH 12.1, first derive the concentration of OH- from the pH value, and then use the dilution formula c1V1 = c2V2 to determine the required volume of the concentrated solution to make 3.73 L of the diluted solution.
Step-by-step explanation:
The question pertains to the preparation of a diluted potassium hydroxide (KOH) solution (pH = 12.1) from a more concentrated KOH solution (0.885 M). To find the volume of the concentrated KOH needed, one must first determine the molarity of the target solution using the provided pH value.
pH = -log[H3O+]; therefore, [H3O+] = 10-pH = 10-12.1. Because KOH is a strong base, it dissociates completely in water, yielding OH- in a one-to-one ratio. The pOH can be calculated using the relation pOH = 14 - pH. Once the concentration of OH- is found, use the formula c1V1 = c2V2 to calculate the required volume of the initial 0.885 M KOH solution to obtain the 3.73 L of the target solution.