If the dipole moment of toluene and nitro-benzene are 0.43 D and 3.93 D then what is the expected dipole moment of p -nitro toluene ?

Question

If the dipole moment of toluene and nitro-benzene are 0.43 D and 3.93 D then what is the expected dipole moment of p -nitro toluene ? (A) 3.50 D (B) 2.18 D (C) 4.36 D (D) 5.30 D

Tardigrade Admin · Accepted Answer

Methyl group has +I effect and —NO2 group has -I effext Therefore, in p-nitro toluene the dipole moments of —CH3 and —NO2 groups act in the same direction So, the resultant dipole moment is additive i.e., 3.93+0.43=4.36 debye <img class="img-fluid question-image" alt="image" src="https://cdn.tardigrade.in/img/question/chemistry/be4c7d83e574990f52bbba128ff8c53f-.jpeg" />

Q. If the dipole moment of toluene and nitro-benzene are $0.43 D$ and $3.93 D$ then what is the expected dipole moment of $p$ -nitro toluene ?

3.50 D

2.18 D

4.36 D

5.30 D

Methyl group has $+ I$ effect and $— N O_{2}$ group has $- I$ effext
Therefore, in p-nitro toluene the dipole moments of $— C H_{3}$ and $— N O_{2}$ groups act in the same direction
So, the resultant dipole moment is additive i.e., $3.93 + 0.43 = 4.36$ debye

Q. If the dipole moment of toluene and nitro-benzene are 0.43D and 3.93D then what is the expected dipole moment of p -nitro toluene ?