Determine the pH of a 1x10^-4M solution of Ca(OH)2?

Answer 1

A few steps to do this problem

The Ca(OH)2 will ionize and yield 2 moles of OH- from each mole of Ca(OH)2. So you need to double the molarity of the Ca(OH)2 to get the actual concentration of hydroxide ions, i.e. 2 x 10E-4M

Now calculate the negative log of this number and you will have the pOH.

Subtract this number from 14 and you will have the pH.