Zinc And Nickel Synthesis Essay
DETERMINATION OF ZINC AND NICKEL CONCENTRATION BY (1) ION-EXCHANGE CHROMATOGRAPHY FOLLOWED BY CHELOMETRIC TITRATION, AND BY (2) ATOMIC ABSORPTION SPECTROSCOPY OF THE MIXTURE
Experiment 4
Dates of Experiment: 10/14/08 through 10/30/08
Date of Report: 11/7/08
Chem 2262L
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I. Introduction
In this experiment, the zinc and nickel contents of unknowns were tested using two methods. In the first method, nickel and zinc were separated through ion-exchange chromatography and analyzed through chelometric titration. In the second method, the unknown was analyzed through the atomic absorption spectroscopy (AAS) of the mixture.
In and ion-exchange column, the ions are separated due to their tendencies to interact with the fixed phase of the column. In this case, the anion-exchange resin is that fixed phase. Nickel passed through the column unhindered and therefore first. Zinc formed chlorozincate anions that reacted with the resin. It could not pass through the column until a neutral aqueous solution was run through. The elements were determined quantitatively by titration with ethylenediaminetetraacetic acid (EDTA). This method is valued as a good estimate and is used widely because of its use of …show more content…
The expected concentration of nickel in the unknown was 0.00125 M. The concentration was determined to be 0.00068 M and 0.00153 M through EDTA titration and AAS respectively. The percent errors for the values were 45.6% and 69.6% correspondingly. The expected concentration of zinc in the unknown was 0.00121 M. The concentration of zinc was determined to be 0.00391 M and 0.0423 M through EDTA titration and AAS respectively. The percent errors for the values were 223% and 231% in that order. The extremely high error indicates either poor techniques or a contaminated unknown. Due to the reproducibility (high precision) of the results, one may assume that it was indeed a contaminated
Experiment 4
Dates of Experiment: 10/14/08 through 10/30/08
Date of Report: 11/7/08
Chem 2262L
�
I. Introduction
In this experiment, the zinc and nickel contents of unknowns were tested using two methods. In the first method, nickel and zinc were separated through ion-exchange chromatography and analyzed through chelometric titration. In the second method, the unknown was analyzed through the atomic absorption spectroscopy (AAS) of the mixture.
In and ion-exchange column, the ions are separated due to their tendencies to interact with the fixed phase of the column. In this case, the anion-exchange resin is that fixed phase. Nickel passed through the column unhindered and therefore first. Zinc formed chlorozincate anions that reacted with the resin. It could not pass through the column until a neutral aqueous solution was run through. The elements were determined quantitatively by titration with ethylenediaminetetraacetic acid (EDTA). This method is valued as a good estimate and is used widely because of its use of …show more content…
The expected concentration of nickel in the unknown was 0.00125 M. The concentration was determined to be 0.00068 M and 0.00153 M through EDTA titration and AAS respectively. The percent errors for the values were 45.6% and 69.6% correspondingly. The expected concentration of zinc in the unknown was 0.00121 M. The concentration of zinc was determined to be 0.00391 M and 0.0423 M through EDTA titration and AAS respectively. The percent errors for the values were 223% and 231% in that order. The extremely high error indicates either poor techniques or a contaminated unknown. Due to the reproducibility (high precision) of the results, one may assume that it was indeed a contaminated