#Redox Reactions: The Ultimate Guide

Hey there, future AP Chem master! 🌟 Let's dive into redox reactions, the final boss of this unit. Remember, you've already conquered precipitation and acid-base reactions – you got this! 💪

#What are Redox Reactions?

Redox reactions, short for oxidation-reduction reactions, are all about the transfer of electrons between atoms, leading to changes in their oxidation states. Think of it as a game of electron hot potato! 🥔

An oxidation state is like an atom's charge in a compound, showing how many electrons it has gained or lost compared to its neutral state. It's a number, positive or negative, that helps us track electron movement.

• Oxidation: When an atom loses electrons, its oxidation number increases. It's like going up a level! ⬆️

• Reduction: When an atom gains electrons, its oxidation number decreases. It's like going down a level! ⬇️

#Quick Recap:

• Redox reactions involve electron transfer.
• Oxidation is losing electrons (oxidation number increases).
• Reduction is gaining electrons (oxidation number decreases).
• The oxidized substance "donates" electrons to the reduced substance.

Writing out redox reactions shows us exactly how electrons are being transferred. Let's get into the nitty-gritty!

#Assigning Oxidation Numbers

To figure out who's gaining and who's losing, we need to assign oxidation numbers. Here are the rules:

1. Free Elements: (like Br₂, Na, P₄) have an oxidation number of 0.
2. Neutral Molecules: The oxidation numbers of all atoms sum to 0. For example, in IF₆, if iodine's oxidation number is x and fluorine's is y, then x + 6y = 0. 3. Monatomic Ions: The oxidation number equals the ion's charge (e.g., Na⁺ is +1, Cl⁻ is -1).
3. Oxygen: Usually -2, except in peroxides (H₂O₂, O₂⁻²) where it's -1.
4. Hydrogen: Usually +1, except in metal hydrides (LiH, BaH₂) where it's -1.
5. Fluorine: Always -1. Other halogens are usually -1 but can vary.
6. Fractions: Oxida...