Write equations for the half-reactions that occur in the electrolysis of a mixture of molten potassium bromide and molten lithium bromide.

Verified step by step guidance

1. Identify the ions present in the molten mixture: Potassium bromide (KBr) dissociates into K⁺ and Br⁻ ions, while lithium bromide (LiBr) dissociates into Li⁺ and Br⁻ ions.
2. Determine the possible half-reactions at the cathode: At the cathode, reduction occurs. The possible reduction reactions are K⁺ + e⁻ → K and Li⁺ + e⁻ → Li.
3. Determine the possible half-reactions at the anode: At the anode, oxidation occurs. The possible oxidation reaction is 2Br⁻ → Br₂ + 2e⁻.
4. Consider the standard reduction potentials: Potassium and lithium have very negative standard reduction potentials, indicating they are strong reducing agents. Bromine has a more positive potential, making it more likely to be oxidized.
5. Write the half-reactions: Based on the reduction potentials, the half-reaction at the cathode is likely to be Li⁺ + e⁻ → Li, and at the anode, it is 2Br⁻ → Br₂ + 2e⁻.

Key Concepts

Electrolysis

Electrolysis is a chemical process that uses electrical energy to drive a non-spontaneous reaction. In this process, an electric current is passed through an electrolyte, causing the decomposition of the compound into its constituent elements. The reactions occur at the electrodes: oxidation at the anode and reduction at the cathode.

Half-Reactions

Half-reactions are the individual oxidation or reduction reactions that occur during electrochemical processes. Each half-reaction shows the transfer of electrons and the change in oxidation states of the species involved. In electrolysis, the half-reactions help to identify which species are oxidized and which are reduced at the electrodes.

Ionic Compounds in Electrolysis

Ionic compounds, such as potassium bromide (KBr) and lithium bromide (LiBr), dissociate into their respective ions when molten. During electrolysis, these ions migrate towards the electrodes, where they undergo oxidation or reduction. Understanding the behavior of these ions is crucial for predicting the products of the electrolysis process.