Arrange the following in decreasing order of reactivity towards EAS (electrophilic aromatic substitu

Question

Arrange the following in decreasing order of reactivity towards EAS (electrophilic aromatic substitution)

Professor PC Thomas Classes · Answer

(a) $-\mathrm{CH}_3>-\mathrm{CD}_3>-\mathrm{CT}_3$
Order of hyperconjugation on the basis of bond energy. Strong bond means less hyperconjugation.