colorimetrylab - 0.005 M 25 mL 0.4164 2 nd 0.005 M 12.5 mL...

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Week of October 13, 2008 CH116-J1 Colorimetry 1. The Spectrophotometer. The spectrophotometer that we used in the laboratory was connected to a computer, on which its screen the absorbency results were shown. The spectrophotometer contains a chamber in which a cuvette filled with a solution can be placed in to be read. A light at a certain wavelength is shone onto the sample, which absorbs the light. The light that is refracted is then measured by a photodetector to calculate absorbency. 2. Absorbencies. Absorbency is higher for solutions with higher concentrations because there are more molecules of solute to absorb and refract light. 3. The Calibration Curve. C 1 (M) V 1 (mL) C 2 (M) V 2 (mL) A Stock 0.02 M 12.5 mL 0.01 M 25 mL 0.8800 1 st 0.01 M 12.5 mL
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Unformatted text preview: 0.005 M 25 mL 0.4164 2 nd 0.005 M 12.5 mL 0.0025 M 25 mL 0.2019 3 rd 0.0937 The relationship between concentration and absorbency is a simple one to one ratio. Absorbency increases as the same rate that the concentration does. The graph is acceptable because it shows this connection. 4. The Preparation of the Complex Ion. As ammonia was added to copper(II) sulfate pentahydrate, the solution turned a cloudy blue color. The precipitate making up the cloudiness was Cu(OH) 2 . As more ammonia was added, the solution became a clear, dark blue color. This new solution includes [Cu(NH3) 4 ] 2+ . 5. Concentration of the Unknown. The concentration of the unknown was 1.51468 0.01727 M....
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This note was uploaded on 08/07/2009 for the course CH 116 taught by Professor March during the Spring '09 term at University of Alabama at Birmingham.

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