Using the appropriate ksp value from appendix d in the textbook, calculate the ph of a saturated solution of ca(oh)2 .

The ph of a saturated solution of Ca(OH)2 is 12.35

CALCULATION:
For the reaction 
     Ca(OH)2 → Ca2+ + 2OH- 
we will use the Ksp expression to solve for the concentration [OH-] and then use the acid base concepts to get the pH:
     Ksp = [Ca2+][OH-]^2

The listed Ksp value is 5.5 x 10^-6. Substituting this to the Ksp expression, we have
     Ksp = 5.5 x 10^-6 = (s) (2s)^2 = 4s^3
     s3 = 5.5x10^-6 / 4

Taking the cube root, we now have
     s = cube root of (5.5x10^-6 / 4)s
        = 0.01112

We know that the value of [OH-] is actually equal to 2s:
     [OH-] = 2s = 2 * 0.01112 = 0.02224 M

We can now calculate for pOH:          
     pOH = - log [OH-]
              = -log(0.02224)
              = 1.65

Therefore, the pH is
     pH = 14 - pOH
           = 14 - 1.65
           = 12.35

C. By doing extra work with Paul's father's horses.

Explanation:

Through process of elimination, B can go, because he's not saying to directly ask his father. Then, A, is saying keep his temper in check for Paul's father, which is not true, it's for his own father.

Lastly, I would eliminate D because in the excerpt, it says nothing about particularly talking to his father.