A student in our class transfers 1.00 mL sample of vinegar (acetic acid) solution into an erlenmeyer flask and adds to it some distilled water and a few drops of phenolphthalein indicator. The solution is then titrated with 6.70 mL of 0.150 mol/L calcium hydroxide solution. Calculate a) The molarity of acetic acid (Ans: 2.01 mol/L) b) The mass percent acetic acid in the vinegar solution. The density of vinegar solution is 1.01 g/mL (Ans: 11.9 %)