Why are pH levels between 0 and 14 only, not 15 and higher?

Answer 1

Asked and anwered several times. Check the previous answers b

Answer 2

That's not entirely true. You can achieve pH values less than 0 and greater than 14.

Consider 2 M HCl. pH = -log [H+] = -log 2 = -0.3 (pH less than zero)

Consider 2 M NaOH. pOH = -log [OH-] = -log 2 = -0.3 and pH = 14 - (-0.3) = 14.3 (pH greater than 14)