Question

Calculate the pH of 10.0mL deionized water plus 5.0mL of 0.10M NaOH

Answer 1

Because NaOH is a strong base, you dont need to write an equilibrium expression; that is \([NaOH]=[OH^-]\)).

Find the molarity (of sodium hydroxide) of the solution, then use it to find pOH and subsequently pH.

\(Molarity=\dfrac{moles~of~NaOH}{L_{solution}}\)

(you can also simply use the dilution formula for this step: \(M_1V_1=M_2V_2\))

Next use \(pOH=-log[OH^-]\)

then pH+pOH=14 to find pH.