Question

How could you determine experimentally whether the compound ${\mathbf{Ga}}_{\mathbf{2}}{\mathbf{Cl}}_{\mathbf{4}}$contains two gallium(II)ions or one gallium(I)ion and one gallium(III)ion? (Hint: Consider the electron configurations of the three possible ions.)

Short answer

Experimentally it is determined that${\mathrm{Ga}}_2{\mathrm{Cl}}_4$ contains$\mathrm{Ga}\left(\mathrm{II}\right)$ ions.

Step-by-step solution

Concept Introduction

Compounds are made up of two or more elements linked together chemically in a certain ratio.

Electrons in an atom's outermost shell are known as valence electrons. The arrangement of electrons around the nucleus of an atom is known as electron configuration.

Electronic Configuration

The answer to this question lies in the electron configuration.

The electron configuration of $\mathrm{Ga}$is $\left[\mathrm{Ar}\right]3{\mathrm{d}}^{10}4{\mathrm{s}}^{2}3{\mathrm{p}}^1$.

$$\begin{gathered} \mathrm{Ga}\left(\mathrm{I}\right):\left[\mathrm{Ar}\right]3{\mathrm{d}}^{10}4{\mathrm{s}}^2 \\ \mathrm{Ga}\left(\mathrm{II}\right):\left[\mathrm{Ar}\right]3{\mathrm{d}}^{10}4{\mathrm{s}}^1 \\ \mathrm{Ga}\left(\mathrm{III}\right):\left[\mathrm{Ar}\right]3{\mathrm{d}}^{10} \end{gathered}$$

Compound present in Ga2Cl4

From the electron configuration of Ga(I), Ga(II), and Ga(III), we can determine their magnetic properties.

When two electrons are paired together in an orbital, or their total spin is 0, they are diamagnetic. Atoms with all diamagnetic electrons are called diamagnetic atoms.

A paramagnetic electron is an unpaired electron. An atom is considered paramagnetic if even one orbital has a net spin. Ga(I) and Ga(III) are diamagnetic, but Ga(II) is paramagnetic.

So, if the given compound is placed in a magnetic field, only the compound containing Ga(II) will be attracted.

Therefore, Ga(II) is present in ${\mathrm{Ga}}_2{\mathrm{Cl}}_4$.