Q21.92P - Chemistry: Molecular Nature Of Matter And Change

Question

In the electrolysis of a molten mixture of RbF and $\mathit{C}\mathit{a}\mathit{C}{\mathit{l}}_{\mathbf{2}}$, identify the product that forms at the negative electrode and at the positive electrode.

Step-by-Step Solution

Answer

At the positive electrode, gas forms, while at the negative electrode, Ca metal forms.

Definition of Electrolysis

The process of decomposing ionic compounds into their constituent elements by passing a direct electric current through the compound in a fluid form is known as electrolysis. At the cathode, cations are reduced, whereas anions are oxidized.

Determining the elements that prepared by electrolysis

As electrolysis process has a lower affinity for electrons, the less electronegative anion forms at the anode, which is the positive electrode, in the electrolysis of molten mixtures. In the periodic table, electronegativity increases as you move to the right and upwards. Between $F^{\mathit{-}}$and $C{l}^{-}$, $C{l}^{-}$ is the less electronegative of the two. At the positive electrode, $C{l}_2$ is produced.

The cation with the highest ionization energy forms in the cathode, which is the negative electrode. When a cation's ionization energy is higher, it means that more energy is required to remove the electron, and there is a stronger attraction between the atom and the electron, making it a more powerful oxidizing agent. Ionization energy grows upwards and to the right in the periodic table. $C{a}^{2+}$ has a larger ionization energy than $R{b}^{+}$, and will thus be transformed to calcium in the negative electrode.