Complete the exercises below. Write complete balanced half-reactions for: a. reduction of nitrate ion to NO in acidic solution, b. oxidation of HNO₂ to NO₂ in acidic solution.

Name: Chemistry: The Central Science
Author: Brown
ISBN: 9780134414232

검증된 단계별 안내

Step 1: Identify the species involved in each half-reaction. For part (a), the nitrate ion (NO₃⁻) is reduced to nitric oxide (NO). For part (b), nitrous acid (HNO₂) is oxidized to nitrogen dioxide (NO₂).

Step 2: Write the unbalanced half-reactions. For part (a), NO₃⁻ → NO. For part (b), HNO₂ → NO₂.

Step 3: Balance the atoms other than oxygen and hydrogen. In both reactions, nitrogen is already balanced.

Step 4: Balance the oxygen atoms by adding H₂O molecules. For part (a), add H₂O to the right side to balance the oxygen atoms. For part (b), add H₂O to the left side.

Step 5: Balance the hydrogen atoms by adding H⁺ ions. For part (a), add H⁺ to the left side. For part (b), add H⁺ to the right side.

주요 개념

질문에 올바르게 답하기 위해 반드시 이해해야 하는 핵심 개념들은 다음과 같습니다.

Half-Reactions

Half-reactions are equations that show either the reduction or oxidation process occurring in a redox reaction. They are essential for balancing redox reactions, as they separate the two processes, allowing for a clearer understanding of electron transfer. Each half-reaction includes the species being oxidized or reduced, along with electrons, protons, and any other necessary ions to balance the charge and mass.

Acidic Solution

An acidic solution is one where the concentration of hydrogen ions (H⁺) is higher than that of hydroxide ions (OH⁻). In redox reactions occurring in acidic conditions, protons are often added to balance the charge in half-reactions. Understanding the role of H⁺ ions is crucial for accurately writing balanced half-reactions, especially when dealing with species that change oxidation states.

Oxidation States

Oxidation states (or oxidation numbers) indicate the degree of oxidation of an atom in a compound. They help in identifying which species is oxidized and which is reduced in a redox reaction. By determining the oxidation states of the reactants and products, one can write balanced half-reactions that reflect the transfer of electrons, ensuring that the overall charge and mass are conserved.