Question

What is the PH of a solution whose [H+] is 0.0007

Answer 1

To determine the pH of the solution. All you would have to do is use the equation:

pH = -log(H3O^+)
pH = - log(0.0007)
pH = 3.15.

Note that H+ and H3O+ are the same, it is more accurate to say H3O+ because of how the H2O molecules become after receiving the additional proton.