Calculate the relative concentrations of phenol (Ka = 1.05 x 10-10) and phenolate

Question

ion in a solution with 0.05 M total phenol (pH = 7.5).

Answer 1

Use the Henderson-Hasselbalch equation.
pH = pKa + log (base/acid)
7.5 = pKa + log b/a
Convert Ka to pKa and solve the above equation for (base)/*acid)
Post your work if you get stuck.

Answer 2

The problem asks for relative concentrations and ratio of base/acid or acid/base will give that to you. I don't think you need the 0.05 M total. However, if you wish to calculate the concentration of each and use that for the ratio, take the base/acid ratio as one equation and solve for (acid) and (base) with the second equation of
(acid) + (base) = 0.05 M
After obtaining the ratio of base to acid