Skip to main content
Ch.9 - Molecular Geometry and Bonding Theories
Chapter 9, Problem 81b

Determine the electron configurations for CN+, CN, and CN-. b. Which species, if any, is paramagnetic?

Verified step by step guidance
1
Identify the total number of electrons for each species: CN+, CN, and CN-. For CN, add the atomic numbers of C (6) and N (7) to get 13 electrons. For CN+, subtract one electron to get 12 electrons. For CN-, add one electron to get 14 electrons.
Write the electron configuration for each species using the Aufbau principle, Hund's rule, and the Pauli exclusion principle. Start filling the orbitals from the lowest energy level (1s) to the highest.
For CN (13 electrons), the electron configuration is: 1s² 2s² 2p⁶ 3σ² 1π⁴ 2π¹.
For CN+ (12 electrons), the electron configuration is: 1s² 2s² 2p⁶ 3σ² 1π⁴.
For CN- (14 electrons), the electron configuration is: 1s² 2s² 2p⁶ 3σ² 1π⁴ 2π². Determine the paramagnetic species by identifying unpaired electrons in the configurations. A species is paramagnetic if it has one or more unpaired electrons.

Verified Solution

Video duration:
6m
This video solution was recommended by our tutors as helpful for the problem above.
Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Electron Configuration

Electron configuration describes the distribution of electrons in an atom or ion across various atomic orbitals. It is represented using a notation that indicates the energy levels and sublevels occupied by electrons. Understanding how to write electron configurations is essential for predicting the chemical behavior and properties of species, including their magnetic characteristics.
Recommended video:
Guided course
01:33
Electron Configuration Example

Ionic Charge and Electron Count

The ionic charge of a species affects its electron count, which is crucial for determining its electron configuration. For example, a neutral molecule has a specific number of electrons, while a positively charged ion (like CN+) has lost an electron, and a negatively charged ion (like CN-) has gained one. This change in electron count directly influences the arrangement of electrons in orbitals.
Recommended video:
Guided course
01:53
Formal Charge

Paramagnetism

Paramagnetism is a property of species that have unpaired electrons, which can be attracted to a magnetic field. To determine if a species is paramagnetic, one must analyze its electron configuration to identify the presence of unpaired electrons. In contrast, species with all electrons paired are diamagnetic and are not attracted to magnetic fields.
Recommended video:
Guided course
01:33
Paramagnetism and Diamagnetism