The reaction of MnO₄^– with oxalic acid (H₂C₂O₄) in acidic solution, yielding Mn²⁺ and CO₂ gas, is widely used to determine the concentration of permanganate solutions. (a) Write a balanced net ionic equation for the reaction.

Verified step by step guidance

1. Identify the reactants and products in the reaction: \( \text{MnO}_4^- \) and \( \text{H}_2\text{C}_2\text{O}_4 \) react to form \( \text{Mn}^{2+} \) and \( \text{CO}_2 \).
2. Determine the oxidation states of manganese in \( \text{MnO}_4^- \) and \( \text{Mn}^{2+} \), and carbon in \( \text{H}_2\text{C}_2\text{O}_4 \) and \( \text{CO}_2 \).
3. Write the half-reaction for the reduction of \( \text{MnO}_4^- \) to \( \text{Mn}^{2+} \) in acidic solution.
4. Write the half-reaction for the oxidation of \( \text{H}_2\text{C}_2\text{O}_4 \) to \( \text{CO}_2 \).
5. Balance the electrons transferred in the oxidation and reduction half-reactions, then combine them to form the balanced net ionic equation.

Key Concepts

Net Ionic Equations

A net ionic equation represents the chemical species that are involved in a reaction, excluding spectator ions that do not participate. It focuses on the actual chemical change occurring in the solution, providing a clearer picture of the reaction's dynamics. To write a net ionic equation, one must first identify the reactants, their states, and the products formed, then eliminate any ions that remain unchanged.

Oxidation-Reduction Reactions

Oxidation-reduction (redox) reactions involve the transfer of electrons between species, resulting in changes in oxidation states. In the given reaction, MnO4- is reduced to Mn2+, while oxalic acid (H2C2O4) is oxidized to CO2. Understanding the roles of oxidizing and reducing agents is crucial for balancing redox reactions and determining the overall electron transfer.

Acidic Solutions

Acidic solutions have a pH less than 7 and contain a higher concentration of hydrogen ions (H+). In the context of the reaction between MnO4- and oxalic acid, the acidic environment is essential for facilitating the redox process and stabilizing the products formed. Recognizing the influence of acidity on reaction mechanisms and equilibria is vital for accurately predicting the outcomes of chemical reactions.