Among the following sets,the most stable ionic species are

Which of the following is the most correct electron displacement for a nucleophilic reaction to take place?

What is the correct order of decreasing acidity for the following compounds?

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 $(-)$.

Select the correct set of substituents for the existence of $-M$ and negative inductive $(-I)$ effects.

Give three points of difference between the inductive effect and the resonance effect.