The most stable canonical structure among the given structures is:

Identify the lowest positive charge developed (indicated by $\delta, \delta_1, \delta_2, \delta_3$) due to the inductive effect in the following compound: $CH_3-CH_2-CH_2-CH_2-Cl$.

Which of the following statements are not correct?
$a$. The energy of resonance hybrid structure is higher than that of the possible canonical structures of the molecule.
$b$. When inductive effect and electromeric effect operate in opposite directions,electromeric effect predominates.
$c$. When the $\pi$ electrons of the multiple bond are transferred to that atom to which the attacking reagent does not get attached,it is known as $+E$ effect.
$d$. The resonance structures with separation of opposite charges are more stable.

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

The correct order of acidity of the following compounds is

Which of the following groups does not show $(-R)$ effect?