Tentukan pH larutan dari 40 gram NaOH ( Ar Na = 23, O = 16, H = 1 ) dalam 2500 ml larutan ?

n NaOH = 40 gr / 40 gr/mol = 1 mol
M = n/v = 1/2.5 = 0.4 M
OH⁻ = 0.4 . 1 = 0.4 M
pOH = 1 - log 4
pH = 13 + log 4 = 13.6 ⇒ Jawab

Mr NaOH = (1 x 23 ) + (1 x 16) + (1 x1) = 40

M = m/mr x 1000 / p
= 40 / 40 x 1000 / 2500
= 40000 / 100000
= 0,4

POH = -log (OH+)
= -log (4 x 10^-1)
= 1 -log 4
= 1 - 0,6 = 0,4

PH = 14 - POH
= 14 - 0,4
= 13,6