Question

Is it that for both E1 and E2 mechanisms order of reactivity is

3^o​​​​ > 2^o > 1^o​​​ carbocation

Answer 1

Due to the fact that E1 reactions create a carbocationintermediate, rules present in Sn1 reactions still apply. As expected,tertiary carbocations are favored oversecondary, primary and methyl's. ...Secondary and Tertiary carbons form more stable carbocations, thus this formation occurs quite rapidly.
so the order is 3°>2°>1°

For E2 reactions;

The order is 3°>2°>1° And I think this order is correct because the transition state of the tertiary alkyl halide will be better stabilized by more hyperconjugating structures as compared to the secondary and primary halides.