Problem 92 - Chemistry: An Atoms-Focused Approach

Question

When \(\mathrm{Ag}_{2} \mathrm{O}\) reacts with peroxodisulfate \(\left(\mathrm{S}_{2} \mathrm{O}_{8}^{2-}\right)\) ion (a powerful oxidizing agent), \(\mathrm{AgO}\) is produced. Crystallographic and magnetic analyses of AgO suggest that it is not simply \(\mathrm{Ag}(\mathrm{II})\) oxide, but rather a blend of \(\mathrm{Ag}(\mathrm{I})\) and \(\mathrm{Ag}(\mathrm{III})\) in a square planar environment. The \(\mathrm{Ag}^{2+}\) ion is paramagnetic but, like \(\mathrm{AgO}, \mathrm{Ag}^{+}\) and \(\mathrm{Ag}^{3+}\) are diamagnetic. Explain why.

Step-by-Step Solution

Answer

Answer: Ag(II) ion is paramagnetic because it has one unpaired electron in its 4d orbital, which causes attraction to a magnetic field. In contrast, Ag(I) and Ag(III) ions are diamagnetic because all of their electrons are paired in their 4d orbitals, leading to repulsion from a magnetic field.

Step 1: 1. Recall the concept of electronic configuration.

Electronic configuration describes the arrangement of electrons in the energy levels, sublevels, and orbitals of an atom. In the case of silver (Ag) ions, we will focus on the outermost d-orbital since the 4d10 and 5s1 electrons are lost when forming ions.

Step 2: 2. Write down the electronic configuration of Ag ions

The electronic configuration of neutral silver (Ag) is [Kr]4d^105s^1. When Ag loses or gains electrons, the different ions are formed: - Ag(I): [Kr]4d^10 - Ag(II): [Kr]4d^9 - Ag(III): [Kr]4d^8

Step 3: 3. Recall the concept of paramagnetic and diamagnetic ions

An ion is paramagnetic if it has unpaired electrons, and it is diamagnetic if all of its electrons are paired. Paramagnetic ions are attracted to a magnetic field, while diamagnetic ions are repelled by it.

Step 4: 4. Determine the magnetic properties of Ag(I), Ag(II), and Ag(III) ions

Based on their electronic configurations: - Ag(I): [Kr]4d^10 has all electrons paired, meaning it is diamagnetic. - Ag(II): [Kr]4d^9 has one unpaired electron, meaning it is paramagnetic. - Ag(III): [Kr]4d^8 has all electrons paired, meaning it is diamagnetic.

Step 5: 5. Explain why Ag(II) is paramagnetic while Ag(I) and Ag(III) ions are diamagnetic

Ag(II) ion has one unpaired electron in its 4d orbital, making it paramagnetic and attracted to a magnetic field. On the other hand, Ag(I) and Ag(III) ions have all electrons paired in their 4d orbitals, making them diamagnetic and repelled by a magnetic field. This explains the observed magnetic behavior of these silver ions.

Key Concepts

Paramagnetic

An ion is considered paramagnetic if it contains unpaired electrons. These unpaired electrons create a magnetic moment, making the ion attracted to external magnetic fields. When assessing paramagnetism, it's essential to look at the electronic configuration of the ion.

For example,

• In the case of Ag(II), its electronic configuration is ewline [Kr]4d\(^9\).
• Here, one electron in the 4d orbital is unpaired, leading to its paramagnetic nature.

Unpaired electrons act like tiny magnets themselves, aligning with external magnets, and thus showing magnetic properties.

Understanding which electrons are unpaired requires a close examination of the atomic structure, specifically focusing on the d-orbitals in transition elements like silver.

Diamagnetic

Diamagnetic ions have all their electrons paired. This complete pairing results in no net magnetic moment, making these ions repel from magnetic fields. When electrons are paired, the magnetic fields they generate cancel out.

In the context of silver ions:

• Ag(I), with an electronic configuration of [Kr]4d\(^{10}\), has a full 10 electrons in its 4d orbital.
• Ag(III), with [Kr]4d\(^8\), pairs all of its 8 electrons as well.

This pairing in Ag(I) and Ag(III) results in their diamagnetic properties. Both ions show no attraction to magnets because their electron spins cancel each other out.

Diamagnetism is a fundamental property observed universally when all electron spins within a substance are paired up.

Silver Ions

Silver ions,

• Ag(I), Ag(II), and Ag(III), each possess distinct electronic configurations affecting their magnetic properties.
• These ions demonstrate the d-block elements' complex behavior due to electron configuration.

In its neutral form, silver (Ag) has the configuration [Kr]4d\(^{10}\)5s\(^1\). Upon forming ions:

• Ag(I) is [Kr]4d\(^{10}\), losing the 5s electron.
• Ag(II) becomes [Kr]4d\(^9\), losing both 5s and one d-electron.
• Ag(III) is [Kr]4d\(^8\), losing an additional d-electron.

These configurations explain why:

• Ag(I) and Ag(III) are diamagnetic with paired d-electrons.
• Ag(II) remains paramagnetic with one unpaired electron in the 4d orbitals.

Silver ions thus exhibit varied magnetic properties depending on their specific electronic setups.