This is an experimental lab that tested if drinking water passes the United States maximum phosphate standard. The results of this lab can help the American who drink the water know if there are too much phosphate in the water. Each group made a Potassium phosphate dilution from a stock solution. The concentration of the solution that needed to made affected the amount of Potassium phosphate that was diluted. To create a calibration curve, each group used the different concentrated Potassium phosphate solutions in their test. 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 …show more content…
The problem is that too much phosphates in water cause eutrophication. Eutrophication can cause harmful living conditions for the animals and plants that live in the water. It can also affect the organisms who lives in areas surrounding the water. Humans are affect when they consume this water. There is a United States maximum standard for phosphate in drinking water which is 3.0 mg/L. The purpose of the lab is to figure the concentration of the unknown solution by using the equation of the coordination curve formed by the absorbance of the solution of known …show more content…
The color that was chose to be shined through the sample was purple. The spectrophotometer was set at a wavelength of 400nm to represent the purple color. It was zeroed using the blank meaning the spectrophotometer read zero as absorbance amount. The blank consisted of 5mL of water and 2.5 mL AVM and it was placed in cuvette. A solution with a known concentration of 2.0x10-4 M was used in the spectrometer. For this solution, 5 mL of the solution with 2.5 mL of AMV was placed in the cuvette. The cuvette was placed inside of spectrophotometer and the amount of absorbance was recorded. This procedure that involves a solution with a known concentration was repeated for the concentrations:1.0x10-4 M,5.0x10-5 M,2.0x10-5M, and1.0x10-5M.A unknown solution absorbance was measured by putting 5 mL of unknown solution with 2.5 mL AMV in a cuvette. The cuvette was placed in the spectrophotometer and the amount of absorbance was recorded. The procedure that deals with the unknown solution was repeated 2 more times with the same solution and the same amount of solution and AMV. The average of the three unknown solution was calculated and the concentration of the unknown solution was
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
Figure 2: The absorabancy 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.
... samples before the incubation of 108 seconds. Then the 100 µL of colour reagent was put to the sample, merged and incubated for further 10 minutes. The absorbance at 615nm and 700nm wavelengths was calculated on the samples in the Cobas analyser and the sample concentration was measure according to :
ε should be all same for three experiments so error occurred here. Source of this error might be little water or moisture inside colorimeter before starting new experiment. This could affect absorbance of wavelength by colorimeter. Also, I used 45°C graph to determine the order of ferroin because when I plotted all three graphs for 40°C, zero-order graph had higher percentage of R^2, than first-order graph. It must have been human mistake as my lab partner forgot to measure for every 120 seconds but randomly recorded four points instead. (120, 240, 430, 540)
After working through many calculations I came out with an average constant of 280, an accurate measurement. Although my readings caused me to have an accurate final answer, they were not precise. My values for the equilibrium constant varied greatly in some of ten trials, ranging from a low of 260 to a high of 320. Other contributions to the value of the constant would be the accuracy of the measuring devices, the purity of the solution and the accuracy of the best-fit line drawn on the graph. Since one of these solutions is clear and the other is colored their Concentrations can easily be found. The solutions can be simply put into a spectrometer and the absorbance will reveal how much of the colored solution resides in the solution. Your results in part one of the experiment can be used to create a graph with which you can make a best fit line and find values for the absorbencies in part two. This information can then be used to calculate the equilibrium constant in all or ten trials and an average can be taken. It allows the student to view first hand exactly what happens at equilibrium and then put this knowledge to
Using the spectrophotometer, the absorption of each sample was measured by scanning the wavelengths. After calibrating the spectrophotometer with the blank test tube, each sample was placed into the spectrophotometer and read at 360nm. Observations were continued for each pigment sample increasing the wavelength by 20nm increments. Once these absorbance values were recorded, absorption spectra for each pigment were graphed.
Alkaline Phosphatase (APase) is an important enzyme in pre-diagnostic treatments making it an intensely studied enzyme. In order to fully understand the biochemical properties of enzymes, a kinetic explanation is essential. The kinetic assessment allows for a mechanism on how the enzyme functions. The experiment performed outlines the kinetic assessment for the purification of APase, which was purified in latter experiments through the lysis of E.coli’s bacterial cell wall. This kinetic experiment exploits the catalytic process of APase; APase catalyzes a hydrolysis reaction to produce an inorganic phosphate and alcohol via an intermediate complex.1 Using the Michaelis-Menton model for kinetic characteristics, the kinetic values of APase were found by evaluating the enzymatic rate using a paranitrophenyl phosphate (PNPP) substrate. This model uses an equation to describe enzymatic rates, by relating the
The periodic table contains many different kinds of elements which are placed accordingly on the table. Potassium is in the alkali metals which is placed in group 1 of the table, alkali metals are among the most active metals. This element was found in 1801 by a man named Humphry Davy. Although the element does not have many uses in pure form as a compound it has many important purposes. Potassium is naturally in the human body if levels become too low or too high then it could cause problems for the individual. Low levels of potassium could cause muscle problems such as cramping and the muscle feeling weak, the person could have a hard time walking or holding onto objects. A serious concern would be the effects on the heart as it causes blood pressure to increase and abnormal heart rhythms.
Spectrophotometry is a widely used method to calculate how much light is absorbed by a chemical substance. This is done by measuring the intensity of light as it passes through a sample solution. The principle of this method is that a compound absorbs or transmits light over a certain wavelength from which the measurement can be used to calculate the concentration of a known chemical substance.
The purpose of this lab was to analyse how light and color is created inside an atom in order to deduce what an unknown chemical compound was. We did two different experiments in order to examine how light is created and changed. In one, we looked at how chemical compounds affected a flame’s color, and to determine what the unknown salt contains. In the other lab, we looked at how atoms create light, and how it is displayed on the elements individual spectral line.
We were not given any instructions either to shake or not to shake the test tubes with the coloured solutions before inserting them in the spectrophotometer to read the absorbance. By shaking each test tube a certain number of times before putting it in the spectrophotometer could have improved the accuracy of the of absorbance of the solutions.
The data from the chromatography portion of the experiment showed that the least polar of the pigments would travel the most and the most polar would travel the least; chlorophyll b was the most polar and carotene was the least polar. The spectrophotometric portion of our experiment support this as well by showing us what wavelengths the pigments reflected and absorbed. With any experiment, however, are there sources of error. One source of error with this experiment would include not cleaning the cuvettes before placing them in the spectrophotometer. The smallest fingerprints or particles can lead to an inaccurate transmittance reading. Also, not using the reference cuvette when changing wavelengths is a source of error because it will lead to an inaccurate reading. Sources of error when using the chromatography paper include, too much or too little time for the solvent to ascend up the paper and the possibility that the solvent level may be too high. When studying photosynthetic wavelengths and pigments, it is known that, depending on the plant, some pigments are absorbed during photosynthesis while others are not. Pigments absorb only the light energy that is necessary in carrying out photosynthesis. This knowledge can assist in determining what areas
We took pictures of each other’s data once finished with the lab. For the paper chromatography, students began by grinding 5g of spinach along with 2g of anhydrous magnesium sulfate. Students added hexanes and acetone as specified by the lab protocols. Once, the solvent was a dark green color, we placed it in a centrifuge and transfer the liquid portion of the solution into a test tube. Throughout this portion of the experiment, students used weighting paper as a funnel poring the indicated solution as stated by the protocol, for instance pouring silica gel and sand into the column. After, we poured about 3ml of Hexanes into the column, making sure not to let the column dry. We then added, spinach extract to the column—after, we added about 1ml of hexanes. Adding hexanes caused the solution to gain a yellow colored band. We added hexanes until the yellow band reached the bottom of the column, thus began to collect all the yellow pigment into a test tube. Once the elutant become colorless, we once again placed a waste basket under it. Finally, we collected the green pigment into another test tube by a 70%/ 30% mixture and a bit of acetone. Once the two colored bands were collected, we obtained the wavelengths of each colored band using the