Write a balanced equation for the overall cell reaction in the following galvanic cell, and tell why inert electrodes are required at the anode and cathode.Pt(s) | Br-(aq) | Br2(l2) || Cl2(g) | Cl-(aq) || Pt(s)

Verified step by step guidance

1. Identify the half-reactions occurring at the anode and cathode. The anode involves the oxidation of bromide ions (Br-) to bromine (Br2), and the cathode involves the reduction of chlorine gas (Cl2) to chloride ions (Cl-).
2. Write the oxidation half-reaction: \( 2 \text{Br}^- (aq) \rightarrow \text{Br}_2 (l) + 2e^- \).
3. Write the reduction half-reaction: \( \text{Cl}_2 (g) + 2e^- \rightarrow 2 \text{Cl}^- (aq) \).
4. Combine the two half-reactions to form the overall balanced cell reaction: \( 2 \text{Br}^- (aq) + \text{Cl}_2 (g) \rightarrow \text{Br}_2 (l) + 2 \text{Cl}^- (aq) \).
5. Inert electrodes, such as platinum (Pt), are required because they do not participate in the chemical reaction. They provide a surface for the electron transfer to occur without interfering with the reactants or products.

Key Concepts

Galvanic Cell

A galvanic cell is an electrochemical cell that converts chemical energy into electrical energy through spontaneous redox reactions. It consists of two half-cells, each containing an electrode and an electrolyte. The flow of electrons from the anode to the cathode generates an electric current, which can be harnessed for work. Understanding the components and functioning of a galvanic cell is essential for writing balanced equations for the overall cell reaction.

Inert Electrodes

Inert electrodes, such as platinum, do not participate in the chemical reactions occurring in the cell but serve as a surface for the oxidation and reduction reactions to take place. They are crucial in cases where the reactants or products are in solution or gas phases, as they provide a conductive surface without interfering with the reaction. Their presence ensures that the electron transfer can occur efficiently without altering the chemical species involved.

Balancing Redox Reactions

Balancing redox reactions involves ensuring that both mass and charge are conserved in the overall reaction. This process includes identifying the oxidation and reduction half-reactions, balancing the number of electrons transferred, and combining them to form a complete balanced equation. Mastery of this concept is vital for accurately representing the overall cell reaction in a galvanic cell, as it reflects the stoichiometry of the reactants and products involved.