cause there are less binding sites available for Copper II to bind on the resin

Cause there are less binding sites available for

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cause there are less binding sites available for Copper (II) to bind on the resin. (MIT Open Courseware, 2011). As stated earlier, another factor that affects ion exchange is rate flow of the mobile phase. A very fast rate flow will not lead to any reaction since the Copper (II) ions will not be able to approach the binding sites since it was not given enough time to displace H + which can therefore result to a lower measured value. A slower reaction however, will lead to a higher measured value and better separation, but it will not be observ- able under normal operating condi- tions. (MIT Open Courseware, 2011). Re-use of the cation exchange resin To be able to reuse the resin (now containing Copper (II) and other cations), the resin must be first sub- merged again in concentrated acid, since Copper reacts very slowly with dilute acids since it is less reactive than Hydrogen in the metal reactiv- ity series. Therefore, the use of con- centrated acid will hasten the process according to Le Chatelier’s Principle. (Petrucci, et.al., 2011). CONCLUSION The three trials of titration of the eluate and washings required 2.5, 2.6, and 2.5 mL of the standardized 0.100 M NaOH solution, respectively. Since the amount of volume of reacted NaOH is consistent, it can be deduced that the data is precise, and most likely accurate as well. The calculated ppm of Cu 2+ are as follows: 157.28, 163.57, and 157.28, respectively. The relative standard deviation (RSD) of the values is at 22.786. The calculated ppm of Cu 2+ are also within the values stated in the Confidence Interval (95%). These results indicate that the experiment was a success, since there were definitely no outliers, there was high precision among the data, and that the data gathered was all within the confidence interval. If this experiment was to be repeated, it is recommended that to check the correspondence among the data, the analyte solution be divided equally with one half’s cation content is to be checked with cation exchange chromatography, while the other half be precipitated with a standardized H 2 S solution in order for the Copper in the solution to be precipitated as Cu 2 S. However, this process is only effective for solutions that contain mostly copper with only trace amounts of other ions since they may co-precipitate along with the copper as a sulphide. (Petrucci, et.al., 2011). Like many other experiments, ion exchange chromatography also has numerous sources of errors, first of which is the uncontrolled rate flow, which might lead to a lower calculated amount of cation concentration since the cations will not displace the H + instantaneously. Another source of error is when the resin was not immersed/stored in concentrated strong acid solution prior to use. When the resin is not stored in concentrated acid prior to
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use, the cations and other impurities bound to it may not have been removed and thus produce a lower amount of displaced H + and a lower calculated amount of total cation concentration. (Rieman, Walton.
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