2
$\begingroup$

Is $\ce{K_2Cr_2O_7}$ diamagnetic or paramagnetic?
While näive theory predicts it's diamagnetic, but we can't be sure.
I cannot find any literature on this topic.
Nor does Wiki has that information.
Even Chem spider doesn't.
I don't know about any other reliable sources.

$\endgroup$
2
  • $\begingroup$ Related: doi.org/10.1002/crat.19740090109 $\endgroup$
    – user79161
    Commented May 24, 2019 at 8:48
  • 2
    $\begingroup$ I don't know, but ... KMnO4 is slightly paramagnetic, usually attributed to the Van Vleck mechanism. This requires a low lying excited electronic state, and KMnO4 has one, reflected in its purple colour. The colour of K2Cr2O7 is due to the same mechanism as KMnO4, but it being orange rather than purple suggests the difference in energies is larger, and so the Van Vleck paramagnetism is smaller. Now the gap needs to be quite small otherwise the diagmagnetic term is larger than the Van Vleck one. So it may be that this increase in energy gap results in K2Cr2O7 being diamagnetic - don't know. $\endgroup$
    – Ian Bush
    Commented May 24, 2019 at 8:49

0

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Browse other questions tagged or ask your own question.