A solution of NaOH(aq) contains 5.4 g of NaOH(s) per 100.0 mL of solution. Calculate the pH and the pOH of the solution at 25 °C.

Answer 1

First, calculate M NaOH.
mols NaOH = grams/molar mass = ?
M = mols/L = mols/0.1 L = ? That gives you the (NaOH) and that is the same as the (OH^-)
Now, pOH = -log(OH)^-
and pH + pOH = pKw = 14. Calculate pH from this.