Food Preservative Lab Report
Michael Pitner
Chem 253- TA: Gia Hoang
Lab 1: Effect of pH on a Food Preservative
9-1-2011
Purpose
The purpose of this lab was to determine if a new substance forms when sodium benzoate is placed in a simulated stomach acid.
Theory
Benzoic acid can be found in a wide variety of plants. It is used as a natural preservative in many foods. Sodium benzoate, the salt of benzoic acid, has become a more popular choice as a food preservative because it is more soluble in water than benzoic acid. Many food items found today are preserved with sodium benzoate.
Reaction
Reaction: sodium benzoate + hydrochloric acid benzoic acid + sodium chloride
Amounts: 2.00 g 5.0 mL 3M …show more content…
The percent yield of this experiment is:
Methods/Procedures
The experiment was done according to the textbook as found on pages 40-47 using the Standard Scale directions.
Safety issues that were accounted for were that both sodium benzoate and benzoic acid are irritants. Safety goggles were worn and care was taken to ensure that none spilled onto skin or clothes. Hydrochloric acid is a strong acid and is very corrosive. Care was taken not to get any on clothes, skin, or into eyes.
Observations/Results After the sodium benzoate was mixed into the water and the HCl was added, the solution underwent a color change from a clear substance to a white substance. Also, a precipitate began to form. This precipitate was a dry, white solid with a mass of .754 g.
Discussion/Conclusion My results seem to be a little askew. While the experiment was done correctly and the calculations correct, not enough of the product was transferred from the flask to the filter to the vial. Had a greater amount have been transferred, the results would have reflected a well done experiment. In the end, pH affected the food preservative sodium benzoate by turning it into benzoic acid under stomach
Chem 253- TA: Gia Hoang
Lab 1: Effect of pH on a Food Preservative
9-1-2011
Purpose
The purpose of this lab was to determine if a new substance forms when sodium benzoate is placed in a simulated stomach acid.
Theory
Benzoic acid can be found in a wide variety of plants. It is used as a natural preservative in many foods. Sodium benzoate, the salt of benzoic acid, has become a more popular choice as a food preservative because it is more soluble in water than benzoic acid. Many food items found today are preserved with sodium benzoate.
Reaction
Reaction: sodium benzoate + hydrochloric acid benzoic acid + sodium chloride
Amounts: 2.00 g 5.0 mL 3M …show more content…
The percent yield of this experiment is:
Methods/Procedures
The experiment was done according to the textbook as found on pages 40-47 using the Standard Scale directions.
Safety issues that were accounted for were that both sodium benzoate and benzoic acid are irritants. Safety goggles were worn and care was taken to ensure that none spilled onto skin or clothes. Hydrochloric acid is a strong acid and is very corrosive. Care was taken not to get any on clothes, skin, or into eyes.
Observations/Results After the sodium benzoate was mixed into the water and the HCl was added, the solution underwent a color change from a clear substance to a white substance. Also, a precipitate began to form. This precipitate was a dry, white solid with a mass of .754 g.
Discussion/Conclusion My results seem to be a little askew. While the experiment was done correctly and the calculations correct, not enough of the product was transferred from the flask to the filter to the vial. Had a greater amount have been transferred, the results would have reflected a well done experiment. In the end, pH affected the food preservative sodium benzoate by turning it into benzoic acid under stomach