User:Sarah Burkhard/Notebook/471 Nano Notebook/2017/02/01

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Optical activity of Gold Hydroxide Complexes Today we will measure the optical activity of Gold tetrachloride at different pH. With increasing pH, the hydroxide concentration increases and the potential of OH- replacing Cl- in gold tetrachloride increases. To what extend gold tetrachloride complexes are affected will be seen from changing absorption values. The DI water has an initial pH of 5.7. This means our effective concentration of OH- is 10^-8.3 mol/L. Since we will be conducting pH measurements throughout the whole semester, we spent a considerable amount of time on figuring out an effective way to adjust the pH. We decided that we will add an equal amount of 5 mM NaOH (equal to the 5mM HAuCL4 ) each time to a solution. We will then adjust the volume with neutralized water (measure pH of water and add NaOH). We will then adjust the pH with 1 M NaOH.