Which of the following compounds has dipole moment approximately equal to that of chlorobenzene? — Chemical Bonding Chemistry Question

💡 Solution & Explanation

Step 1: Let the dipole moment of a single C-Cl bond be x. In meta-dichlorobenzene, the angle between the two C-Cl bond dipoles is exactly 120°. Step 2: Use the vector addition formula: μ_net = √(x^2 + x^2 + 2x^2 * cos(120°)) = √(2x^2 - x^2) = x. Step 3: Since the vector sum of two identical dipoles at 120° is equal to the magnitude of a single dipole (x), the dipole moment of m-dichlorobenzene is approximately equal to that of chlorobenzene (option b).