I have a solution which contains unknown amount of dissolved ferric chloride (FeCl3) and hydrochloric acid. Can I use the titration method with NaOH to determine the concentration of HCl? I was concerned since dissolved FeCl3 is also acidic, and the fact that NaOH will try to neutralize it as well. Thus the titration result may not be accurate. Further more the solution is a brown to begin with, what indicator should I use to clearly tell the end point?