Question

1. Chemists define pH as "the negative logarithm of the concentration of protons". In mathematical terms:
pH = - log [H+]

What is the pH of a solution whose [H+] is 0.0007 M?

i got it as 7.0 i know it is wrong

2. What is the [H+] in a solution having a pOH of 6 ?
isn't it supposed to add to 14? so 8? but it didn't work

Answer 1

a.
pH = -log(H^+)
pH = -log(7E-4)
pH = -(-3.15)
pH = 3.15

b.
pH + pOH = pKw = 14
pH + 6 = 14
pH = 8
The problems asks for (H^+); therefore,
pH = -log(H^+)
8 = -log(H^+)
-8 = log(H^+)
(H^+) = 1E-8