Results - absorbance of four unknown concentrations The...

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BIO 181 Dr. Sweat Results Four procedures were conducted using the technique of spectrophotometry to identify solutes and their concentrations. For the first procedure, a graph was constructed (see Fig. 1) plotting absorbance versus wavelength that represents the absorption spectrum for Cobalt Chloride (CoCl 2 ). The wavelength at the peak of absorbance was found to be 530nm. Next, a standard curve was constructed (see Fig. 2) for Cobalt Chloride (CoCl 2 ) using six known concentrations, or standards, at the peak absorbance wavelength. The linear relationship between concentration and absorbance results in a straight line for the standard curve graph. By referring to this graph and drawing intersecting lines at the horizontal axis, we conducted the third procedure to determine
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Unformatted text preview: absorbance of four unknown concentrations. The absorbance and concentrations were recorded as follows; unknown Tube #2= 0.826 A / 32.5 mg/mL, unknown Tube #3= 0.432 A / 15.0 mg/mL, unknown tube #4= 0.426 A / 14.0 mg/mL unknown tube #10= 0.754 A / 28.5 mg/mL. For the last procedure, a graph was constructed (see Fig. 3) plotting relative absorption of light versus wavelength that represents the absorption spectrum of Chlorophyll. The proper blank for determining the absorption of Chlorophyll in a plant extract is Acetone. After completing the procedure, we concluded the wavelengths that are least absorbed by Chlorophyll are greens and yellows, while the wavelengths that are most absorbed are blues and reds....
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This note was uploaded on 09/14/2011 for the course BIO 181 taught by Professor Sweat during the Spring '11 term at ASU.

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