Complete and balance the following half-reactions. In each case, indicate whether the half-reaction is an oxidation or a reduction. (a) Sn²⁺(aq) → Sn⁴⁺(aq) (acidic solution) (b) TiO₂(s) → Ti²⁺(aq) (acidic solution) (c) ClO₃^-(aq) → Cl^-(aq) (acidic solution) (d) N₂(g) → NH₄⁺(aq) (acidic solution)

Verified step by step guidance

1. Identify the oxidation states of titanium in TiO2 and Ti^{2+}.
2. Determine the change in oxidation state to identify if it is oxidation or reduction.
3. Balance the oxygen atoms by adding H2O molecules to the side lacking oxygen.
4. Balance the hydrogen atoms by adding H+ ions to the side lacking hydrogen.
5. Balance the charge by adding electrons to the more positive side to equalize the charge on both sides.

Key Concepts

Oxidation and Reduction

Oxidation and reduction are chemical processes that involve the transfer of electrons between species. Oxidation refers to the loss of electrons, resulting in an increase in oxidation state, while reduction involves the gain of electrons, leading to a decrease in oxidation state. Understanding these concepts is crucial for identifying the nature of half-reactions in redox processes.

Balancing Half-Reactions

Balancing half-reactions is essential in redox chemistry to ensure that both mass and charge are conserved. This involves adjusting coefficients for reactants and products, and may require adding electrons, protons, or water molecules. In acidic solutions, protons (H+) are often added to balance the charge, making it important to follow systematic steps for accurate balancing.

Acidic Solution Conditions

In an acidic solution, the presence of H+ ions influences the balancing of half-reactions. This environment affects how we balance charges and mass, particularly when adding protons and water molecules. Recognizing the conditions of the solution is vital for correctly completing and balancing the half-reaction, as it dictates the species involved in the reaction.