We were given an unknown to identify using UV-VIS spec based on the wavelength of maximum absorbance and the shape of the curve produced. One of the questions at the end of the report is "Are you able to identify the chromophore? Describe." I'm not exactly sure what they mean by the question. I know that a chromophore is the portion of a molecule that is responsible for its color but I'm not sure if they mean were we able to identify the unknown compound given to us or if we were able to determine the portion that provides the color (which was a white powder, colorless in solution)
I don't know which you were supposed to do but the question asked if you were able to identify the group responsible and not were you able to identify the compound. The sentence in question may have been just a poorly worded question.
yea that's what i was thinking too, that it was meant to ask if i was able to identify my unknown because through just uv-vis i can't think of any way that would be able to identify the specific portion of the compound besides looking up the molecular structure
In the context of your experiment with UV-VIS spectroscopy, when the question asks if you are able to identify the chromophore and describe it, it is referring to your ability to determine the portion of the unknown compound responsible for its color. As you correctly pointed out, a chromophore is the part of a molecule that gives it color.
Since the unknown compound you were working with is a white powder and colorless in solution, it is reasonable to assume that it does not have an obvious chromophore. However, the UV-VIS spectroscopy can provide insights into the presence of any conjugated systems within the compound, which can potentially be the chromophoric part responsible for color.
To answer the question about identifying the chromophore, you should interpret the UV-VIS spectrum of the unknown compound. Look for any distinct peaks or patterns in the absorption curve, especially in the UV and visible regions. This information can indicate the presence of conjugated systems, which are often associated with chromophores.
In your description, you can mention whether you were able to identify any distinct absorption peaks, the wavelength(s) of maximum absorbance, and any observations about the shape of the curve. Additionally, you can discuss whether there is any evidence of conjugated systems that might suggest the presence of a chromophore, even if the compound itself does not exhibit visible color.
Remember, the ability to identify the chromophore might be challenging if the unknown compound is colorless. However, by analyzing the UV-VIS spectrum and making connections with existing knowledge of chromophores and conjugated systems, you can provide an informed description of the likelihood of a chromophore being present and discuss any relevant findings.