The main purpose of this research lab was to determine the level of phosphate content within the colas and the relationship with phosphate and upset stomachs. Following, the logic was if the capacity of the phosphate was buffered, this will solve upset stomachs of individuals. However, the amount of phosphate cannot be directly determined so a series of steps and calculations to gain an understanding of the overall project. (Cooper,2008)
For starters, proper usage of a spectrophotometer must be mastered, and an understanding the relationship between absorbance, concentration, and percent transmittance must be gained. To gain a complete understanding, three different tests were done with three different samples of food coloring and the determination of the analytical wavelength was completed by using the spectrophotometer. The analytic wavelength is determined by the highest absorption rate of the component tested. Refer to Table 1 the results.
The same process using KMnO4 while finding the relationship between concentration and percent transmittance, which is the number of photons that can pass through without being absorbed. The goal of finding the percentage transmittance was to find a concentration that gives an absorption amount that would be able to give a percentage between 15 and 85. The first attempt a percentage of 13.8
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However, the concentration level of everyday items is too concentrated to be analyzed by a spectrophotometer; Therefore, a 2-step dilution had to be done and was completed by diluting the phosphate content with 0.001M and again with 0.0002M. Following, 2mL of .0002M sample of phosphate with ammonium vanadomolybdate (AVM) to allow visibility because phosphate ions cannot absorb ultraviolet or visible light and AVM will allow absorbance without disturbing the phosphate content. Based on the results, the analytical wavelength was found, and a calibration curve was made. Table 3/Graph
Data from Table 1. confirms the theory that as the concentration of glucose increases so will the absorbance of the solution when examined with the glucose oxidase/horseradish peroxidase assay. Glucose within the context of this assay is determined by the amount of ferricyanide, determined by absornace, which is produced in a one to one ratio.1 Furthermore when examining the glucose standards, a linear calibration curve was able to be produced (shown as Figure 1). Noted the R2 value of the y = 1.808x - 0.0125 trend line is 0.9958, which is statistically considered linear. From this calibration curve the absorbance values of unknowns samples can be compared, and the correlated glucose concentration can then be approximated.
Absorbance was defined as: log I_o/I where I_o is incident light and I is the transmitted light. Fluorescence emission spectrum is different from fluorescence excitation spectrum because it records different wavelengths of chemical s...
The analyzed yellow#5 wavelength was determined to 395nm because the actual wavelength 427nm was restricted in the Micro lab. The R2 value of the graph is 0.9827, and the level of data accuracy it indicated extremely weak data correlation. The first one dilution data points excluded from the standard curve because the point is not in the linear curve. The first concentration and absorbance value are the highest point in the graph that cannot connect as linear with another data point. After removing the first data point, the standard curve is clear and make
The absorbance of these mixtures is measured at a suitable wavelength. If 'x' mole/litre are added to (1-x) mole/litre of M and if C1, C2
700 0.03 0.01 0 0 0.028. 720 0.01 0.01 0 0 0.02 0. Figure 2: The absorption spectrum shows how absorbent the photosynthetic pigments are at different wavelengths of light. Note: Green light is between 500 to 570 nm and red light is between 630 to 720 nm.
The lab utilized a spectrophotometer to figure out the absorbance of the five different Potassium phosphate solution and the absorbance of an unknown concentration solution. The absorbance of the unknown solution was used
Because it is a way of knowing the pressure that the blood is putting on the walls of arteries and veins.
...s the change in the temperature of both of these batches, 6°C for the pure, and 13°C for the crude. In this final sub-section of the Characterization of Aspirin, the values of absorbance were recorded. Initially, 0.0566 grams and 0.0590 grams of pure and crude Aspirin respectively were obtained and each individually placed into beakers (400 milliliter) and had 250.0 milliliters of distilled water added to them. From each beaker, a tiny amount of the just dissolved solutions was transferred to a cuvette, one cuvette for each type of aspirin. Each cuvette was placed into the ultraviolent spectroscopy mechanism which was connected to a computer and absorbance spectrum values were obtained at 298 nm (Figure 5) (0.1987 pure aspirin, and 0.9549 crude aspirin).
The independent variable for this experiment is the enzyme concentration, and the range chosen is from 1% to 5% with the measurements of 1, 2, 4, and 5%. The dependant variable to be measured is the absorbance of the absorbance of the solution within a colorimeter, Equipments: Iodine solution: used to test for present of starch - Amylase solution - 1% starch solution - 1 pipette - 3 syringes - 8 test tubes – Stop clock - Water bath at 37oc - Distilled water- colorimeter Method: = == ==
The experiment, focuses on the effects of acidic drinks on teeth. In this experiment, the scientist is trying to answer which liquids; Arnold Palmer, Coffee, Coca Cola, V8 Splash Tropical Blend, and crest pro-health toothpaste, affect your tooth enamel the most. The Independent Variable are four ounces of each liquid, and the dependent variable is the staining of teeth. The Constants are the toothpaste, toothbrush, the amount of time the eggs stay in the liquid, and the type of eggs used. The units used while measuring the effect of liquids on teeth is ounces.
In undertaking the experiment, the hypothesis “if the number of Alka Seltzer tablets reacted increases, then the maximum rate of reaction will increase,” was formed. When graphing the relationship between the maximum rate of reaction and the number of Alka Seltzer tablets reacting, Graph 7 produced a line of best fit with a constant increasing slope that passed through the origin (0,0). This is characteristic of linear graphs, which have the general equation, y=mx, where m is the slope, a constant term, and y and x are changing variables that are directly proportional (i.e. y ∝x). Hence, it can be deduced that Graph 7 is a linear graph, and that there is a linear relationship between the maximum rate of reaction and the number of Alka Seltzer tablets, where they are directly proportional. That is, as the number of Alka Seltzer tablets increased, the maximum rate of reaction increased, supporting the hypothesis. As the true value of the maximum rate of reaction per Alka Seltzer tablet was not known, and a value for comparison was unavailable, the accuracy of the results could not be determined. However, due to the scatter in Graphs 2 to 7, it was evident that the results had low precision. In future, repeating the experiment using different and/or new apparatus will aid in detecting systematic errors and improve the accuracy and validity of the results.
The same procedure was done using 10ml of CV and 20ml of sodium hydroxide, both separately diluted to 50ml and added in a large beaker. The absorbance was recorded. In the last trial, 10ml of CV, 10ml of NaOH were diluted to 50ml. Before adding the two mixtures, 1ml of soap was added to the NaOH solution and then poured into a large beaker, along with the CV. Absorbance was recorded and the materials
In this experiment, the effect of pepsin was tested in different environments and pH, with the pepsin “digesting” the egg white. The result to occur was meant to be different levels of effervescence, which correlates with the relative activity of the pepsin. pH has a critical effect on different enzymes, and is clearly evident in this experiment. The relative activity of the pepsin was highest in hydrochloric acid, and lowest in detergent, with reasons of why this may occur. A possible explanation for why the pepsin activity was highest in the hydrochloric acid, due to the body secreting that in the stomach, creating a similar environment leading to the best results, with another example simply being that the pH resembled a pH similar to the
By comparing the absorption spectrum of phenol red in basic and acidic solutions, the red (basic) form had a much narrower and higher λ max (560nm) than the yellow form (420nm). As a result, the red form of phenol red was more sensitive with pH changes and it was used in for an assay in part B. In part B, the standard calibration curve was generated in order to determine the concentration of phenol red in the unknown 2B. From the slope, the average concentration of the unknown 2B was 0.001009 M. More importantly, the % difference of unknown trials was low (0.40%), indicating the high precision and reliability of the result. In part C, the pKa of the phenol red can be determined by plotting pH as a function of log ([A-])/([HA]). The pKa and
It changes from blue to red with acids but loses its colour in the presence of certain chemicals, one of which is vitamin C. DCPIP solution can be used to test for the presence of vitamin C in foods. Hypothesis Orange juice has the highest content of vitamin C. Citrus fruits have a higher content of vitamin C. The orange and lemon juice contain more vitamin C than the pineapple juice. Furthermore, as lemons are more acidic than oranges, I predict that the orange juice will contain more vitamin C than the lemon juice. Vitamin C affects, the ph the more vitamin C the higher the ph. Variables Independent Variables Different fruit juices (Pineapple, orange and lemon).