What reaction will take place at the cathode and the anode when each of the following is electrolyzed? a. molten \(\mathrm{KF}\) b. molten \(\mathrm{CuCl}_{2}\) c. molten \(\mathrm{MgI}_{2}\)

Electrolyte decomposition is a fundamental process in the field of electrochemistry, involving the breakdown of chemical compounds in their molten or aqueous form when an electric current is passed through them.

The electrolyte, a substance containing free ions, is crucial for this process as it conducts electricity due to the movement of these ions, which are attracted to the oppositely charged electrodes. In the context of the given exercise, substances like \textbf{KF}, \textbf{CuCl}\(_2\), and \textbf{MgI}\(_2\) are decomposed into their respective ions before undergoing further chemical changes at the electrodes.

Understanding the decomposition of electrolytes is vital to grasp the fundamentals of electrolysis, which has practical applications ranging from the extraction of metals to electroplating and the production of chemical compounds.

The cathode reduction reaction refers to the process at the cathode during electrolysis, where positive ions, or cations, gain electrons and are reduced to their elemental form. This process is key to understanding how metals can be extracted from their ionic compounds using electrolysis.

In the exercise provided, potassium (\textbf{K}\(^+\)), copper (\textbf{Cu}\(^{2+}\)), and magnesium (\textbf{Mg}\(^{2+}\)) ions are attracted to the negatively charged cathode. Here, they each acquire electrons (\textbf{e}\(^-\)) from the cathode. For instance, the reduction reaction for \textbf{KF} at the cathode is represented by \textbf{K}\(^+\) + \textbf{e}\(^-\) → \textbf{K}. Such reactions demonstrate the process of gaining electrons, leading to the metal existing in its pure elemental form after the reaction is complete.

Conversely, the anode oxidation reaction occurs at the anode, where negative ions, or anions, lose electrons and are oxidized. This forms part of the overall electrolysis process, where electrons are removed from certain chemical species.

For example, fluoride (\textbf{F}\(^-\)) from \textbf{KF}, chloride (\textbf{Cl}\(^-\)) from \textbf{CuCl}\(_2\), and iodide (\textbf{I}\(^-\)) from \textbf{MgI}\(_2\) are attracted to the positively charged anode during electrolysis. These anions release electrons to the anode, resulting in the formation of \textbf{F}\(_2\), \textbf{Cl}\(_2\), and \textbf{I}\(_2\), respectively, as shown in the above exercise. These species are generally gases and can be collected as the by-products of the electrolysis process.

Molten salt electrolysis is a specific type of electrolysis applied to ionic compounds that are in their liquid state due to high temperatures. Here, the compound, such as a halide salt, is first melted to obtain a molten bath, which acts as an excellent conductive medium due to the free movement of ions.

This technique is extensively used in the extraction of reactive metals from their salts. In each of the cases from the exercise - \textbf{KF}, \textbf{CuCl}\(_2\), and \textbf{MgI}\(_2\) - the molten state allows for direct, clean extraction of metal at the cathode and the corresponding non-metal at the anode. Each has its application in industry, such as producing aluminum from bauxite via molten salt electrolysis of aluminum oxide. Simplifying these complex processes provides valuable insight for students, making applications in real-world scenarios more approachable.