Question

Which of the following has the larger dipole moment: CN or CN ⁻?
1) CN
2) CN ⁻

Answer 1

The dipole moment of CN⁻ is larger than that of CN due to the presence of an additional lone pair of electrons on nitrogen.

Step-by-step explanation:

The dipole moment of a molecule depends on the electronegativity difference between the bonded atoms and the bond length. CN and CN⁻ are isoelectronic, meaning they have the same number of electrons. However, CN has a triple bond between carbon and nitrogen, while CN⁻ has a double bond and an additional lone pair of electrons on nitrogen. The presence of the additional lone pair leads to a larger dipole moment in CN⁻ compared to CN.