1. The problem statement, all variables and given/known data I have to find the pH of a 8.57x10-10M HNO3 solution. 2. Relevant equations HNO3 + H20 <--> H3O+ + NO3- pH= -log[H3O+] 3. The attempt at a solution my theory was that the hydronium ion concentration would be the hydronium ion concentration in water (1x10-14 M) plus the concentration of the nitric acid (8.57x10-10 M... because it fully dissociates). then take the negative log of it. i came up with a pH of 6.99 but my chemistry professor told me that i did it wrong and it is actually more complicated and could involve equilibrium. what did i do wrong?