The chemical reaction in question is the reaction between Luminol and hydrogen peroxide. Is the wavelength of light generated through this reaction dependent on the concentration of either reactant?

I am inclined to believe that the answer is no but I do not know why. I could not find an experiment that tested this online either and I'm wondering if anyone else tried this. If I do turn out to be correct, what other factors affect the wavelength of the light emitted in this specific reaction (pressure, temperature, etc.)? or is it fixed?

  • 3
    $\begingroup$ Since the individual photons emitted are the result of electronic transactions in a specific molecule then only things that affect the structure of that molecule will affect the wavelength. $\endgroup$
    – matt_black
    Nov 17 at 10:23
  • 1
    $\begingroup$ If the concentration of the reactants are changed, the light intensity will change, but not the wavelength of the emitted light. $\endgroup$
    – Maurice
    Nov 17 at 10:41
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    $\begingroup$ Generally, absorption and emission spectrum of dissolved substance or intermediate product may change with concentration, directly, or indirectly via higher temperature because of reaction enthalpy. But it would at the best rather slight shift than significant change. $\endgroup$
    – Poutnik
    Nov 17 at 10:53
  • $\begingroup$ See the table here: researchgate.net/figure/…. $\endgroup$
    – Ed V
    Nov 17 at 11:59
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    $\begingroup$ @EdV, I was exactly thinking the same thing- solvatochromism of luminol in the excited state will slightly change the emission maximum. $\endgroup$
    – M. Farooq
    Nov 17 at 13:32

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