The first cation to be separated from the known

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The first cation to be separated from the known solution was Hg I. In the individual analysis, it was shown to react with the first reagent added, 6M HCl. When the two were combined, a milky white precipitate formed. The 6M HCl reacted with the Hg 2 (NO 3 ) 2 (aq). When HCl was added to the unknown solution in the second part of the experiment, a milky white precipitate was also formed. This justified the fact that it could be assumed that the Hg I cation was present in the unknown solution since the HgCl (s) precipitate was present after the reaction. The second reagent added was the 6M NH 3 (aq). During the individual analysis, this reagent was observed to form a black precipitate with the Hg I. Milky white precipitates were seen to form during this reaction with the Pb II, as well as a Red/ Brown . With the Cd II cation, white precipitate formed from the reaction. The precipitates that formed from these two reactions were Fe(OH) 3 (s) and Cd(OH) 2 (s). When the unknown solution was tested, a brown precipitate, similar in color to the Fe III cation reaction in the first part of the experiment, formed. Fe(OH) 3 (s) precipitate was present after the reaction. Cd II cation reacted with the 6M NaOH reagent in the individual analysis. A white precipitate was formed because the Nitrate salt Cd(NO 3 ) 2 (aq) reacted with the 6M NaOH and formed a Cd(OH) 2 (s) precipitate. When the unknown solution was tested, and 6M NaOH was added, the same results were supported by the
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findings of the first part of the experiment. The unknown solution could therefore be said to contain the Cd II cation. A source of error that could have occurred during the experiment was not centrifuging the solutions an adequate amount of time, as well as the machine not doing it well enough on the flat surface. Without getting isolating all of each cation could have impeded on the results of the unknown solution, this would have left overs to affect the results of the actual experiment. If the reagent had to be split between the designated cation and also remnants of the previous one the reagent also reacts with, could hinder the complete reaction and separation of the cation that step was supposed to isolate. Another problem would have the use of the materials and whether or not they were truly clean or not. If they were not truly clean this would have contaminated the solutions which would throw off the results and impede reactions or create precipitates that are not there. A problem area in the analysis of this experiment was the integration of the knowledge of the first part of the experiment and the second part. If the actual flow chart was not completed correctly or understood then all the results from the second week would have been off and not correctly distinguished.
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