This is problem involves multiple steps. First you need to find the pH value. Your calculations should look like this: pH= -log(H+) pH= -log(4.17e-4) pH= 3.38 Next, you need to find the pOH value. Your calculations should look this: pH+ pOH= 14 3.38+pOH=14 pOH= 14-3.38 pOH=10.62 If you answered "A" you found the pH. If you answered "C" you forgot to put the negative sign when finding the pH.