Spectrophotometric Reference for Inorganics?

[mishima]

I am looking for absorbance spectra and extinction coefficients (molar absorptivities) for common inorganic substances like potassium and sodium salts. I am only finding this information for biological substances.

Am I misinterpreting what the spectrophotometer can do? I would like to, for example, use Beer's Law to calculate concentration of a salt in solution after measuring absorbance with a known extinction coefficient.

 

[Borek]

Visible?

Does the NaCl solution look colored?

Infrared? UV?

 

[mishima]

I mean salts in general, like potassium permanganate or copper (II) nitrate. I am unaware if sodium chloride can be used with a spectrophotometer; I was under the impression that some could not.

would like an absorbance spectrum (absorbance vs. wavelength), so all wavelengths. I would have thought this information would be tabulated somewhere, like a chemical handbook, but I am not finding it.

 

[Yanick]

You can try here: http://webbook.nist.gov/chemistry/

Failing that you should just try to find the original research. It will likely be old which makes it (kind of) easier to find them for free.

 

[LudusRex]

I can confirm that spectrophotometry is a commonly used technique for measuring the absorbance spectra and extinction coefficients of inorganic substances. However, the availability of this information may vary depending on the specific substance and its characteristics.

While there may be a larger amount of data available for biological substances, there are also numerous resources that provide absorbance spectra and extinction coefficients for inorganic substances such as potassium and sodium salts. These can be found in scientific databases, textbooks, and research articles.

It is important to note that the use of Beer's Law to calculate concentration from absorbance requires certain assumptions to be met, such as the substance being in a pure solution and the solution being dilute. If these conditions are not met, the calculated concentration may not be accurate.

In summary, spectrophotometry is a valuable tool for studying inorganic substances, and there is likely information available for the substances you are interested in. However, it is important to carefully consider the limitations and assumptions of using this technique for concentration calculations.