To clean a cloged drain, 26g of sodium hydroxide is added to water to make 150mL of solution. What are the pH and pOH values for the solution?

mols NaOH = grams/molar mass = 26/40 = 0.65

Molarity = mols/L = 0.65/0,150 == 4.33 M so (OH^-) = 4.33 M
pOH = - log (OH^-) = -log 4.33 = - 0,63. Yes, that's a minus 0.63 because the OH is > 1.0 M. The pOH is 0 if OH is 1.0 M
pH + pOH = pKw = pKw = 14. You know pKw and pOH, solve for pH