Answer:
0.00316
Explanation:
You have to use the following equation:
[tex]pH=-log[H^+][/tex]
You are given the pH and need to find the concentration of H+. Plug in the given components and solve.
[tex]2.5=-log[H^+]\\H^+ = 10^{-2.5}\\H^+=0.00316[/tex]
The concentration of H is 0.00316.