I did an acid/base titration with acetic acid and sodium hydroxide to determine the concentration of acetic acid present in vinegar but I'm not quite sure how to go about calculating the concentration of it. First things first we dissolved 25ml of vinegar into 250ml of water and filled the burette to its 0 mark with this solution. We then added 25ml of 0.1M NaOH solution to an Erlenmeyer flask and added a few drops of phenolphtalein indicator. Then we titrated and watched as the liquid in the flask went from bright pink to completely clear then recorded the volume in the burette. I this formula M2V2/b = M1V1/a for calculating concentration but I'm wondering if I have to calculate the amount of H+ ions from the acetic acid and OH- ions from the NaOH present in the solutions before I can go ahead. I'm not quite sure how this works for a weak acid is there a general rule like "1 dissociated H+ ion for every 2 moles of weak acid while the ratio is 1:1 for a strong acid?" One other quick question on the side. I have 25ml of 0.1M NaOH solution so to calculate the moles present I just type 25/1000 x 0.1 into my calculator but this gives me a ridiculously low number which I doubt the teacher would expect us to deal with. Am I doing something wrong here?