According to the Hume-Rothery rules for the substitutional solid solutions the atomic sizes of the the solute and solvent must not differ by more than 15%. Why should it be so?

Amides require much harsher conditions to hydrolyse than its ester homologue. An explanation given is that the orbitals holding the lone pair on the nitrogen overlaps with the C=O π-bond to give conjugation, thus introducing a "partial" π-bond between nitrogen and the carbonyl carbon. Consequentl...

I am referencing this article: https://en.wikipedia.org/wiki/Rotational_temperature So, I see that $\theta _R = \frac{(h/2\pi)^2}{2Ik_b}$. I took the value of $I$ from https://cccbdb.nist.gov/mieigen2x.asp. However, when I do the calculations for $\theta _R$ by plugging in the numbers, I get $$\t...

I read that the molecular orbital diagram of cyclobutadiene predicts that it should have a diradical nature as it has two unpaired electrons in two degenerate non bonding orbitals (one in each). Why does this diradical state exist only in cyclobutadiene? Shouldn't other anti aromatic compounds, l...