A 25.0 mL sample of acetic acid (of unknown concentration) was added to an Erlenmeyer flask. A few drops of phenolphthalein (an acid-base indicator) were added to this acid solution. The acid solution was titrated with a standard solution of 0.500 M of potassium hydroxide, which was used to fill a buret. The initial volume reading on the buret was 2.35 mL. At the end of the titration (when the solution turned pink) the final volume reading on the buret was 24.87 mL
I am having trouble understanding where to start with this problem. How do I calculate the molar concentration of the acetic acid solution that was titrated?