Determination of the Acid Content in a Food ProductPaula Moltzan Bryan Novas (L-42)11.15.17Introduction:The purpose of this experiment was to analyze the percent acetic acid content in vinegarby titration. This is important because a common question chemist need to answer is how muchof something is present in a sample. This can be done by titrations which is a method of volumetric analysis. Titrations can measure the concentrations of acids or bases in solutions, these concentrations help to calculate the formula mass. Indicators are added to titrations because they help to detect the equivalence point or the “end point”. Which is when the solution color changes colors and signals that the equivalence point has been reached. The first step of this experiment was to pipet precisely 5.0 mL of the ~6.0 M sodium hydroxide solution into a 250-mL volumetric flask. Then dilute the flask to the volume mark withdistilled water, then put a stopper on the flask and mix completely. Then transfer the diluted sodium hydroxide solution to a 400-mL beaker and mix again. After, clean the volumetric flask by rinsing multiple times with distilled water. Next, the burette was rinsed with a few milliliters of the sodium hydroxide solution from Part A three times, draining the rinsings into a 600-mL waste beaker. Then, the buret was placed into the burette clamp on a ring stand and the burettewas filled with the diluted sodium hydroxide solution and the starting level was recorded. Next 20 mL of pickle juice (PJ) was acquired and put into a beaker and 5 mL of the PJ was pipetted into a 125 mL Erlenmeyer flask. Then 50mL of water was added to the PJ and 2-3 drops of the phenolphthalein was also added in to the flask with the PJ solution. Lastly, this solution was titrated slowly with the diluted sodium hydroxide solution until the first bright pink color appears. The titration was stopped as the solution turned and stayed fully pink and the final level of sodium hydroxide in the burette was recorded. The contents were disposed of and the flask was rinsed three times and the titration of the pickle juice was repeated for a total of threetrials. Safety glasses and gloves were required at all times during this experiment. Sodium hydroxide is corrosive, handle with care and if you spill any let your TA know. Anything that ispoured down the drain must be neutralized and followed by water. Solutions of pH≤5 or pH≥9 should never be disposed of down the drain and neutralized solutions have a pH between 6 to 8, 6≥pH≤8. You can check the pH by using the litmus paper. ResultsThe purpose of this experiment was to determine the molar concentration of acetic acid in vinegar by titration. Our results show that the average molarity of acetic acid was 0.4816 M (Equation 1), this was used to calculate the percentage of vinegar in the pickle juice sample. Thecalculated percentage of vinegar in this experiment was found to be 55.05%. Standard pickle juice contains 60% vinegar, with this information we were able to calculate percent error in our experiment (Equation 2). Our percent error was 8.25%, this indicates that in the experiment some errors may have occurred. One factor that could may have affect our experimental results is if the pipet used for transferring the pickle juice to the flask may have potentially been dirty. If some of the pickle juice was stuck in the pipet this would lower the percent of acetic acid found in pickle juice. Thisis because you would have less pickle juice in the original sample, so the amount of NaOH needed to reach the equivalence point would be smaller. With a lower amount of NaOH it would mean we would have a lower amount of acetic acid because the moles of the base (NaOH) equals the moles of the base (acetic). Another potential error could be that determining the true end point of the titration wasdifficult. This is because the food sample would turn pink but then not stay pink so it was hard to determine the exact point in which the solution stayed a vibrant pink. This would also result in a lowered percent of acetic acid in our experiment. If the titration was stopped before the equivalence point was reach there would be a lowered amount of NaOH in the solution, meaning the amount of acetic acid would as be lowered. This could potentially be fixed by knowing the color/shade of pink that the solution was supposed to turn once it reached its “endpoint”. Correct technique is necessary in getting an accurate result and obtaining an accurate set of data in this experiment. Equation 1.M=molesof soluteliters of soltuionEquation 2. percent error=|experimental value−theoretical valuetheorectical value|X