In compound $(X)$,hyperconjugation is present and in $(Y)$,resonance effect is present. What are $X$ and $Y$,respectively?

State True or False for the following statements:
$(i)$ The stability of carbocation is explained by the delocalized structure of hyperconjugation.
$(ii)$ The stability of carbocation is explained by drawing the resonance structure.
$(iii)$ Hyperconjugation effect is $(+)$ or $(-)$.
$(iv)$ Mesomeric effect is $(+)$ or $(-)$.

Which of the following alkyl groups has the maximum $+I$ effect?

Formic acid is a stronger acid than acetic acid. This can be explained using

Which of the following is correct?

What is the type of delocalization involving $\sigma$ bond orbitals called?