Beer’s Law Lab Report Essay

AbstractThe Beers integrity lab was conducted to lay the best wavelength of Co(NO3)26H2O with the use of spectrometry. The results readd that the optimum wavelength to study the absorbance of this common salt was 500nm. It in any case present how transmittance of miniature and absorbance of exculpated are inversely proportionate because absorbance is compute by multiplying transmittance by a negative log. groundingWhen unrivaled is studying chemicals, there are many important factors of significance. The coloring material of a chemical is a useful to a faultl in its study. The lightlying one sees produced by a chemical is the result of both reprimand and absorbance of wavelengths. The wavelengths that are abstracted by a chemical are non visualized. The wavelengths that are reflected back are the colors that one sees. When chemicals are diluted in water system supply, their colors also become diluted. As the chemical is diluted, the molecules blossom a actuate . The more dilute the consequence, the further apart the molecules. As the molecules spread, the color that is reflected becomes less(prenominal) intense because some of the wavelengths are able to pass through the effect without encountering any of the solute.The more wavelengths that are able to pass through a solution without encountering any of the solute, the greater the transmittance. The transmittance can be mathematically metrical by dividing the sum of light that exited the solution (IT) by the amount of original intensity (IO). That value is then multiplied by ascorbic acid to give the percent transmittance (%T)Beers Law is use to yoke and compares the amount of light that has passed through something to the substances it has passed through. The Law is represented by A=abc. A is the absorbance of a solution. The a represents the immersion continuous of the solution creation tested. The b represents the thickness of the solution in centimeters, and c represents th e solutions megabyte or denseness. The A can be calculated by using the negative log of the transmittance (T).  The lab experiment conducted used the salt Co(NO3)26H2O. The Co(NO3)26H2O was diluted in distilled water to four different molarities. The al just about concentrated solution was used to determine the optimal wavelength to study the salt by measuring the transmittance of the Co(NO3)26H2O with twenty different wavelengths of light. Once the optimal wavelength was concluded, the transmittance of the less concentrated Co(NO3)26H2O solutions was also measured. The measurements of the less concentrated solutions was to determine the absorbance constant, a. Finally, the transmittance of an uncharted ingress of Co(NO3)26H2O solution was measured and molarity was determined found on the absorbance constant determined earlier in the experiment.ProcedureA test pipe was prepared with 0.1 M solution of Co(NO3)26H2O in 10mL of distilled water. Half of the .1M solution, 5m L, was drawn up into a pipette and place into another test electron tube with 5mL of deionized water to make a 0.05 M solution. Half of the 0.05 M solution, 5mL was drawn into a pipette and put into a test tube with 5mL of deionized water to make 0.025 M solution. Half of the 0.025 M solution, 5mL, was drawn into a pipette and put into a test tube with 5mL of deionized water to make 0.0125 M solution. A test tube of 10mL of deionized water was also prepared. The bubbles on all test tubes were aloof by tapping on the outside of the test tube. The outside of the tubes were dried off and any fingerprints were removed with paper towels and placed into a test tube rack.An absorbance mass mass spectrometer was zeroed by measuring the transmittance at 400nm with no test tubes in the spectrometer. The spectrometer was then calibrated to vitamin C percent transmittance with the test tube of deionized water. The deionized water was removed from the spectrometer and the 0.1 M solution wa s put inwardly the spectrometer. The transmittance of the solution was recorded and the solution was removed. The wavelength on the spectrometer was changed to 410nm and the deionized water was placed back into the spectrometer and the transmittance was calibrated to one hundred percent.The deionized water was replaced with 0.1 M solution and the transmittance was recorded. This knead was repeated twenty multiplication with the wavelength increasing by 10nm consecutively until the last wavelength, 600nm, was measured. It was necessary to calibrate the spectrometer between to each one change in wavelength. Every change in nanometers had to be measured and calibrated at 100 percent with the manoeuver of deionized water. This maintained accuracy when the transmittance of Co(NO3)26H2O solutions measured.Based on the data gathered, the optimal wavelength was determined and the spectrometer was set to that wavelength. The transmittance was set to 100 with the deionized water. Th e 0.1 M solution replaced the deionized water in the spectrometer chamber and the transmittance was recorded. This process was repeated with 0.05 M, 0.025 M, and 0.0125 M solutions and the transmittance was calibrated to 100 between each solution with the deionized water.Finally, a Co(NO3)26H2O solution with an unknown molarity was provided (unknown B). The wavelength of the spectrometer was not changed. The deionized water was placed in the chamber and calibrated to 100 percent transmittance. The deionized water was removed and replaced with a test tube containing unknown B. The transmittance was recorded to determine what the molarity was. Data afterwards the solutions had been completed, the transmittance was measured at 10nm intervals from 400nm to 600nm. The measurements were determine the wavelength to best study Co(NO3)26H2O. high transmittance present less intentness of the wavelength and lower transmittance demonstrated higher submergence of the wavelength.DiscussionBee rs Law is a law that demonstrates that the absorbance of light at a certain wavelength is directly proportionate to the concentration or molarity of a solution. This was apparent with the naked eye. When making the solutions, 0.291 moles of was added to a test tube with 10mL of deionized water to make a 0.1 M solution. By taking 5mL out of the solution and mixing it with 5mL of deionized water, the number of moles was halved which made the second gear gear solution a 0.05 M solution. When the process had been repeated, it was apparent that the solutions had been diluted based on the color of the solutions in the test tubes. The 0.1 M solution was enthralling more light and was a deep rose color. As the solutions became more dilute, the concentration of the visible color diminished as less light was absorbed to a very pale translucent pink in the 0.0125 M solution.For the first part of the lab, the wavelengths 400-600nm were used. These wavelengths were used to determine the opti mal wavelength when the most light was absorbed by the solution. It was important to calibrate the transmittance to 100% on the spectrometer with the deionized water because there were no solutes to absorb light. The spectrometer was then able to use that calibration to determine how much of the light was absorbed by the solution containing Co(NO3)26H2O by comparing the difference in how much light was absorbed by the detectors in the spectrometer.The spectrometer than calculated the percent transmittance (%T) and displayed the data in a percent. As was shown above in table 1 and graph 1, the %T started high and cease high with percentages over 90. The higher %T demonstrate less light was absorbed by the solution and therefore not the wavelength of light that is absorbed by Co(NO3)26H2O. Toward the middle of the data, 500nm and 510nm, the %T became substantially lower. This demonstrates that Co(NO3)26H2O absorbs wavelengths about 500nm.In the second part of the lab, the different molarity, or concentrations, of solution were measured for %T with a 500nm wavelength. The absorbance was calculated by using the negative log of T. This was done because T and A are inversely proportional. This was demonstrated in table 2 and table 3. These tables confirmed that as T decreases, A increases.The third part of the experiment used the point slope formula to determine a molarity based on an absorbance.The absorbance of light was dependent on the concentration of solute. The variables A and y are both dependent variables and were comparable to one another. The variable x and c were the independent variables. The variable a was the absorption constant and b was the thickness of the solution. In this case, b was equal to 1 cm. Graphs 2 and 3 demonstrated the plotted points and from that, excel calculated a trend line based on the point-slope formula. Graph 3 demonstrated how the estimated molarity of unknown B, based on the point-slope formula, fits the trend line. shutdo wnBeers Law was studied in this lab. The goals of this were to determine optimal wavelength absorption by Co(NO3)26H2O and determine transmittance and absorption from the data collected. The optimal wavelength absorption for Co(NO3)26H2O occurred at 500nm. The data also showed that while the transmittance and absorbance were indirectly proportional from one another, both variables were dependent on the concentration of the solution. Once the data had been collected and unders likewised, an unknown concentration of solution was tested for transmittance. Based on the trend line formed from other concentrations of Co(NO3)26H2O solutions, the molarity was easily calculated to be 0.048.Possible errors that may bewilder occurred during this lab have to do with calibration of the spectrometer. The transmittance values changed second to second so if the quantify was not perfect in measuring the samples, the transmittance would have been erroneous. The transmittances would have been too hi gh (based on experimentation) so the absorbance rates would have been too low. This in turn would have caused the absorbance constant to be too low. If the absorbance constant was too low, the concentration of unknown B would have been calculated too high.