Question

The decreasing order of –I effect of the following is:
I)${R_4}{N^ \oplus }$
II)$N{O_2}$
III)CN
IV)$S{O_3}H$
V)COOH
A.I > II > III > IV > V
B.II > I> III > IV > V
C.I > II > III > V > IV
D.II > I > V > IV > III

Answer 1

Hint: -I effect is described by the magnitude of positive charge on an atom. When the magnitude of positive charge on an atom decreases, the –I effect decreases. Order of –I effect is given below which is useful to find the increasing order of –I effect.
 $
  ^ \oplus N{F_3}{ > ^ \oplus }N{R_3}{ > ^ \oplus }N{H_3} > - N{O_2} > - CN > - S{O_3}H > - CHO > - CO \\
   > - COOH > - COCl > - F > - Cl > - Br > \\
   - I > - OH > - OR > - H \\
 $

Complete step by step answer:
-I effective on electron density in one portion of a molecule due to electron withdrawing or electron donating groups. In covalent bonds between two atoms of unequal electronegativity the atom with higher electronegativity withdraws electron density.
Inductive effect generally considered by the transmitted through the framework of a molecule. The electronegativity of an element is usually a measure of its ability to attract electrons. It is on ring substituent because they are related to the concept of electronegativity.
Hence, the decreasing order of – I effect is given below:
 \[{R_4}{N^ \oplus } > N{O_2} > CN > S{O_3}H > COOH\]

Therefore, option (A) is the correct answer.

Note: The –I effect is the concept of in organic chemistry which refers to the interactions of charge on adjacent atoms. The inductive effect is a direct result of another concept which is known as electronegativity. Electronegativity is the ability of the protons in the nucleus of an atom.