tolong di jawab pertanyaan sih please

H+ = akar Kw x Ka/Kb
= akar 10^-14 x 4,5.10^-4 / 10^-5
= akar 4,5.10^-13
= akar 45.10^-14
= 6,7.10^-7 M
pH = 7 - log 6,7