Find the number of hyperconjugation structures in the isopropyl carbocation.

What is the electromeric effect?

Which one of the nitrogen atoms in $H_2N-NH-CO-NH_2$ (where the atoms are labeled $I, II, III$ as shown in the structure) is the most nucleophilic?

Consider the following structures:
$I.$ $CH_3-CH_2-COOH$
$II.$ $CH_3-CH(Cl)-COOH$
$III.$ $Cl-CH_2-CH_2-COOH$
$IV.$ $CH_3-CH_2-CH_2-COOH$
The correct order of their acidity is

Which of the following represents the hyperconjugation effect?

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