Question

(Copper Ammine Synthesis and UV-Vis Spectroscopic Analysis Lab)

1. Why would a chemist need to perform BOTH a scan across all wavelengths and a scan at a specific wavelength?

2. How will you know if your calibration curve is acceptable?

Answer 1

1.

Scan across all wavelength will provide information about the wavelengths, where this present molecule is absorbing. This can be used to identify the molecule, From this, we can use the lambda max (that is lowest energy maximum) for further experiments. It is better to take the specific wavelength scan for obtaining calibration curves.

2. If calibration curve is a straight line with the concentration of sample under similar conditions (pathlength constant) is an acceptable curve.