Determine the pH of a KOH solution made by mixing 0.251 g KOH with enough water to make 1.0 * 10² mL of solution. A) 1.35 B) 2.35 C) 7.00 D) 11.65 E) 12.65

Question

Quizplus · Accepted Answer

1. First, we need to calculate the number of moles of KOH in the solution:
0.251 g KOH x (1 mol KOH/56.11 g) = 0.00448 mol KOH

2. We need to calculate the concentration (in M) of the KOH solution:
(0.00448 mol KOH) / (0.012 L) = 0.373 M KOH

3. Finally, we can use the definition of pH to calculate the pH of the solution:
pH = 14 - log [H+]
Since KOH is a strong base, it will dissociate completely in water:
KOH → K+ + OH-
So, the concentration of OH- in the solution is equal to the concentration of KOH:
[OH-] = 0.373 M

Now we can substitute into the pH equation:
pH = 14 - log (0.373)
pH = 12.65

Therefore, the answer is E: 12.65.

Determine the PH of a KOH Solution Made by Mixing