Ph Chem Lab

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Experiment 9 - Effects on Vitamin C (with PH) Research Question: How does the change of PH (increase of decrease) effect the amount of vitamin C in a vitamin C solution? Goal of Experiment: Have the opportunity to independently design and perform a scientific study on an aspect of vitamin C decomposition. Hypothesis: I predict that by introducing HCl or NaOH into the vitamin C solution the percentage of vitamin C present in the solution will decrease. Abstract: The purpose of this lab is to determine the effects that changing the PH of a vitamin C solution will have on the concentration of vitamin C. The concentration changes will be calculated after 6 titrations (2 control, 2 with added NaOH, and 2 with added HCl) . Once calculated, these results can be analyzed and will either validate or refute my hypothesis. Introduction (Library Research): Ascorbic acid (vitamin C) is found in orange juice. In this experiment, orange juice made from the concentrate was measured for decreases/increases of off-flavours (furfural and α-terpineol) and for decreases/increases of ascorbic acid. Sodium hydroxide (NaOH) as well as hydrochloric acid (HCl) were added during separate trials to change the PH in the orange juice. An increase of PH from 3.2 to 4.2 enabled the protection of ascorbic acid levels, without increasing the levels of other enzymes. In this experiment, the amount of vitamin C in orange juice before and after the addition of HCl or NaOH was compared. The research was conducted to determine ways to ensure that the quality of a stored orange juice remains as close as possible to that of an initial juice. The orange juice samples were exposed to different levels of PH over certain time periods and as a result, there was data that help suggest ways to improve/ change storage methods of orange to increase its shelf life and to
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