1 / 14

Redox Reactions

Learn how to separate a full equation into oxidation and reduction half-reactions, balance them individually, and combine them to get a fully balanced equation. Includes steps for acidic and basic solutions, with examples provided.

hernandezc
Download Presentation

Redox Reactions

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Redox Reactions 13.1b Complex Half-Rxtns

  2. Half-Reaction Method • separate the full equation into 2 half-reactions: oxidation and reduction • balance each half-reaction separately • add them together to get full balanced equation

  3. Steps for acidic solution • Write 2 separate equations for oxidation and reduction • include any compound containing the element involved

  4. Steps for acidic solution • For each half-reaction: • balance all elements but H and O • balance O using H2O • balance H using H+ • balance charge using electrons (e-)

  5. Steps for acidic solution • If needed, multiply one or both half-reactions by an integer so that number of electrons is equal in both half reactions

  6. Steps for acidic solution • Add the half-reactions together and simplify • Check to be sure all is balanced.

  7. Steps for basic solution • balance using acidic method • add OH- ions equal to #H+ ions to both sides • form water on the side of equation that contains both ions • simplify # of water molecules • check for balance

  8. Example 4x

  9. Example

  10. Acidic Example MnO4–(aq) + Br–(aq)  Mn2+(aq) + Br2(aq) • 1. Determine oxidation and reduction half-reactions: • Oxidation half-reaction: Br–(aq)  Br2(aq) • Reduction half-reaction: MnO4–(aq)  Mn2+(aq)

  11. 2. Balance for atoms other than H and O: Oxidation: 2 Br–(aq)  Br2(aq) Reduction:MnO4–(aq)  Mn2+(aq) 3. Balance for oxygen by adding H2O: • Oxidation: 2 Br–(aq)  Br2(aq) • Reduction:MnO4–(aq)  Mn2+(aq) + 4 H2O(l)

  12. 4. Balance for hydrogen by adding H+: Oxidation: 2 Br–(aq)  Br2(aq) Reduction: MnO4–(aq) + 8 H+(aq)  Mn2+(aq) + 4H2O(l) 5. Balance for charge by adding electrons (e–): Oxidation: 2 Br–(aq)  Br2(aq) + 2 e– Reduction:MnO4–(aq) + 8 H+(aq) +5 e– Mn2+(aq) + 4 H2O(l)

  13. 6. Balance for numbers of electrons by multiplying: • Oxidation:5[2 Br–(aq)  Br2(aq) + 2 e–] • Reduction:2[MnO4–(aq) + 8 H+(aq) +5 e–  Mn2+(aq) + 4 H2O(l)] • 7. Combine and cancel to form one equation: • Oxidation:10 Br–(aq)  5 Br2(aq) + 10 e– • Reduction:2 MnO4–(aq) + 16 H+(aq) +10 e–  2 Mn2+(aq) + 8 H2O(l) 2 MnO4–(aq) + 10 Br–(aq) + 16 H+(aq)  2 Mn2+(aq) + 5 Br2(aq) + 8 H2O(l)

  14. Homework TextbookPage 566 #12 all

More Related