User:Patrick Hampson/Notebook/chem471/2017/02/07

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Measuring Gold-Hydroxide Absorbance at varying pHs ELECTRODE PROCEDURE We battled the electrode today. We calibrated it using calibrating buffer solutions of pH 4, 7, and 10. We also refilled the electrode with the proper solutions, as it had previously been dried out. Solution Preparation + UV-VIS Procedure -We will prepare solutions pH 4-14 -Measure range 800-200 nm in UV-Vis pH 4 | 300 uL 5mM HAuCl4 |-----------------------------| 240 uL 5mM NaOH | 2460 uL neutral H2O pH 5 | 300 uL 5mM HAuCl4 | 1470 uL 1mM NaOH|------------------------------| 1170 uL neutral H2O pH 6 | 300 uL 5mM HAuCl4 | 1497 uL 1 mM NaOH|-----------------------------| 1197 uL neutral H2O pH 7 | 300 uL 5mM HAuCl4 | 300 uL 1 mM NaOH|------------------------------|2400 uL neutral H2O pH 8 | 300 uL 5mM HAuCl4 | 3 uL 1 mM NaOH|-------------| 300 uL 5mM NaOH | 2397 uL neutral H2O 1 mM NaOH |Expected pH: 11| Actual pH: 10.28| 5 mM NaOH |Expected pH: 11.7| Actual pH: 11.4| 1 M NaOH |Expected pH: 14| Actual pH: 13.33| 5 mM HAuCl4 |Expected pH: 2.3| Actual pH: 2.32| Overall these are relatively close to the expected values, but calculations must be adjusted accordingly. Solutions were not measured using UV-VIS today, due to the amount of time we had to commit to dealing with a faulty pH electrode.