Calibration Curve Lab Report

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The calibration curve observed in this investigation was the relationship measured between the concentration of the cobalt solution, or CO(NO3)2, and the absorbance of the wavelength. As it was impossible to measure the true standard curve, the data points and subsequent graphs demonstrated the qualitative information collected and the trend of these values. The calibration curve closely resembled a straight line, with only minimal deviations in either direction. This indicated that the solutions examined and the data attained had a low percentage of error and high accuracy. As the concentration of the cobalt (II) solution decreased, the absorbance also decreased. This direct proportional relationship, explicated by Beer-Lambert’s Law …show more content…
The more obvious and likely was the contamination by over-dilution of the known solution. Despite proper laboratory methods, the possibility of excess DI water or remnants of the previous concentration of the solution being retained in the vessels as they were mixed and transferred from pipette to graduated cylinder to glass test tube, is high. Consequently, in order to decrease this in future investigations, it would be advisable to use a separate pipette and graduated cylinder for each of the ten solutions. Other possible sources of error, not necessarily a factor in this experiment, included: utilizing dirty glassware and cuvettes, using tap water which contains contaminating ions, and not calibrating the spectrophotometer/colorimeter. Limitations to this procedure were that the measurement of cobalt in the soil is only theoretical in this instance, as the investigation does not include any actual soil samples. Furthermore, an aqueous solution and heterogeneous mixed solid would not be realistically comparable to the novice chemist, using the spectrophotometer/colorimeter technique. Other possible limitations, not necessarily a factor in this investigation, included: imprecise volume measurements, incorrect molar calculations, and utilizing the wrong prepared cobalt solution (with unknown concentration).
As defined in the lab manual, there was not enough cobalt in the tested soil samples. For
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The concentration of the cobalt (II) ions in the theoretical soil samples was calculated using spectroscopy; Beer-Lambert’s Law was utilized for calculations and conceptualization. Moreover, with the experimental values produced, the standard curve of absorbance in the varying concentrations of cobalt (II) nitrate were graphed and examined. At the conclusion of the investigation, the results indicated that the theoretical samples did not contain the required quantity of cobalt to maintain the health of the livestock. Additionally, the experimental data confirmed the original hypothesis and established the origin of the sickness in the dairy farm animals.
As the investigation provided evidence to support that there was not enough cobalt in the soil, it was necessary to employ a standard calculation to determine the amount of cobalt (II) nitrate to be added to the soil. It was recommended to the cooperative extension service, that they supplement the soil with approximately 4.9124 mg of cobalt (II) nitrate per 1 mg of soil in all of the livestock

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