How would one be able to identify the lambda max of Cr(III) at a concentration less than 70ppm from a graph? I couldn't post the graph, but I don't understand how one would be able to do this?
The graph had the Chromium Absorbance Spectra of 70ppm for Cr(VI) and Cr(III). Cr(VI) intersects the curve for Cr(III) at one point.
Cr(VI) exhibits 2 absorption bands, one with lambda max of 348nm and a 2nd broader band with lambda max of 435nm.
Cr(III) has 2 absorption bands one with lambda max of 405nm and one with lambda max of 576nm.
To identify the lambda max of Cr(III) at a concentration less than 70ppm from the given graph, you can follow these steps:
1. Start by understanding the graph: Take a careful look at the graph you mentioned with the Chromium Absorbance Spectra of 70ppm for Cr(VI) and Cr(III). Note that Cr(VI) intersects the curve for Cr(III) at one point.
2. Identify the absorption bands: From the information provided, Cr(VI) exhibits two absorption bands, one with a lambda max of 348nm and a second broader band with a lambda max of 435nm. Similarly, Cr(III) has two absorption bands, one with a lambda max of 405nm and another with a lambda max of 576nm.
3. Locate the intersection point: Pay attention to the point where the Cr(VI) and Cr(III) curves intersect. This intersection point indicates the wavelength (lambda) at which both species (Cr(III) and Cr(VI)) have the same absorbance. This point on the graph should give you a specific value for lambda.
4. Determine lambda max of Cr(III): Once you have located the intersection point, the lambda max of Cr(III) can be determined by finding the wavelength (lambda) value on the x-axis at the intersection point on the graph. This value corresponds to the lambda max of Cr(III) at the given concentration.
Note that the lambda max is the wavelength at which the substance (in this case, Cr(III)) exhibits maximum absorbance. By observing the graph and understanding the absorption bands of both Cr(VI) and Cr(III), you can effectively identify the lambda max of Cr(III) even at concentrations less than 70ppm.