Spectrochemical series and wavelength of light (chemistry)?

What is the wavelength of light absorbed by [Co(NH3)6]3+?

a) greater than 7.70 x 10^2 nm

b) less than 2.90 x 10^2 nm

c) between 2.90 x 10^2 nm and 7.70 x 10^2 nm

2 Answers

  • 1 decade ago
    Favorite Answer

    Hi Nicole: I have file of useful data for tackling these and other problems. You might like to start one (I have the spectrochemical series [1] in my file as well). Here are the data for UV/vis spectra:

    Visible light has wavelengths ranging from roughly 300 to 800 nm (nm = 1 x 10-9 m)

    (low E) red = ~700 nm ~19,000 cm-1; green = ~ 525 nm ~19,000 cm-1

    blue = ~475 nm ~ 21,000 cm-1 (high E)

    I know that [Co(NH3)6]3+ is brown so it is absorbing in the visible region (it must be letting through the red and parts of the blue and green). Co(III) is invariably low spin d6 and there are two t2g -> eg spin allowed transitions but this is not needed for this question.

    Let us get the possibilities into a manageble form:

    a) greater than 770 nm

    b) less than 290 nm

    c) between 290 nm and 770 nm

    So c is the answer your instructor is looking for. The cmplx however will almost certainly have absorptions in the UV and will also give IR absorptions due to for example ν(N-H) stretches (~3400 cm-1) but the instructor is the boss. cheers, drp

  • 4 years ago

    >If gravity impacts easy, then can it influence the wavelengths of light.? actually. there's a phenomenon customary as 'gravitational redshift' (if I bear in mind properly) it somewhat is largely what you're suggesting here. >hence, the way we degree the chemical makeup of a techniques away issues in area, should be slightly or perhaps a great deal in blunders because of the fact of light absorption errors from wavelength adjustments. we've customary approximately this effect for an prolonged time, and verify you stunning for it in our calculations. Scientists are no longer that careless.

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