posted by alejandro .
The formula for determining the pH of a solution is pH = -log[H+], where [H+] is the hydrogen ion concentration (in M/L). What is the hydrogen ion concentration of an acid with a pH of 2.5?
-2.5 = log H+
10^-2.5 = H+ = .00316
By the way I do not understand the notation used in your other problem.