PROCEDURE: Hirko, R. Chemistry 112L General Chemistry I Laboratory, Ninth Edition; bluedoor: Minneapolis, 2015; Experiment 4.
Trial P/ppm Abs @ 400 nm / AU Volume beverage / mla Volume dilution water / mla Total volume of diluted sample / mla P in soda / ppm
1 0 .001
2 1.333 .160
3 3.333 .280
4 6.667 .585
U1 2.560 .228 .870 45.610 46.480 205.153
U2 2.607 .232 1.020 50.266 51.386 197.005
U3 3.374 .298 1.196 43.252 49.448 209.244
Ave 204
Unc ±12 RESULTS: The recorded concentrations of phosphoric acid content in Pepsi taken from three trials was found to be 204 ± 12 as listed in Table 1.
Trials 1-4 show the results of the calibration solution which were used to calculate the phosphoric acid concentrations in the …show more content…
However, the results were very far from the known value given by Hirko, a 38.8% error. Each of the three trials had a very high bias, shown by the calculated percent error. As a result, none of the experimental values were statistically equivalent to the known.
If the found results are true, then the phosphoric acid content in Pepsi-Cola is much higher than reported. While this is not inherently dangerous, higher values than reported could potentially cause health problems for those consuming large amounts of the product. On the other hand, the phosphoric acid can potentially be beneficial to health when it comes to bone and oral …show more content…
Because the initial trial contained the reagent, and that was set as the baseline, each of the following trials’ reagent was accounted for; therefore, the final absorption numbers subtracted the reagent number and only read the phosphoric acid absorption numbers. Had the calibration trials been performed initially with water instead of the blank reagent, the results would not have been accurate because the reagent itself absorbs some of the light from the spectrometer. Instead, the results would all have had an even higher bias in the absorption values. A larger path length, such as 450 nm instead of 400 nm would increase the absorption numbers due to more molecules in the path of the light. Additionally, this could scatter the light and raise the numbers even more. Equation 2 shows this to be true; as ι increases, so would the absorbance. These would end up with a steeper (larger) slope on the regression
Trial P/ppm Abs @ 400 nm / AU Volume beverage / mla Volume dilution water / mla Total volume of diluted sample / mla P in soda / ppm
1 0 .001
2 1.333 .160
3 3.333 .280
4 6.667 .585
U1 2.560 .228 .870 45.610 46.480 205.153
U2 2.607 .232 1.020 50.266 51.386 197.005
U3 3.374 .298 1.196 43.252 49.448 209.244
Ave 204
Unc ±12 RESULTS: The recorded concentrations of phosphoric acid content in Pepsi taken from three trials was found to be 204 ± 12 as listed in Table 1.
Trials 1-4 show the results of the calibration solution which were used to calculate the phosphoric acid concentrations in the …show more content…
However, the results were very far from the known value given by Hirko, a 38.8% error. Each of the three trials had a very high bias, shown by the calculated percent error. As a result, none of the experimental values were statistically equivalent to the known.
If the found results are true, then the phosphoric acid content in Pepsi-Cola is much higher than reported. While this is not inherently dangerous, higher values than reported could potentially cause health problems for those consuming large amounts of the product. On the other hand, the phosphoric acid can potentially be beneficial to health when it comes to bone and oral …show more content…
Because the initial trial contained the reagent, and that was set as the baseline, each of the following trials’ reagent was accounted for; therefore, the final absorption numbers subtracted the reagent number and only read the phosphoric acid absorption numbers. Had the calibration trials been performed initially with water instead of the blank reagent, the results would not have been accurate because the reagent itself absorbs some of the light from the spectrometer. Instead, the results would all have had an even higher bias in the absorption values. A larger path length, such as 450 nm instead of 400 nm would increase the absorption numbers due to more molecules in the path of the light. Additionally, this could scatter the light and raise the numbers even more. Equation 2 shows this to be true; as ι increases, so would the absorbance. These would end up with a steeper (larger) slope on the regression