redox

redox. 🔥 REDOX 🔥 💡 what is redox? redox = reduction + oxidation happening at the same time Remember OIL RIG : ● Oxidation Is Loss of electrons 🔥 ● Reduction Is Gain of electrons ❄ 🧠 oxidation vs reduction (3 ways to define) Method Oxidation Reduction 1. Electrons lose electrons gain electrons 2. Oxygen gain oxygen lose oxygen 3. Hydrogen lose hydrogen gain hydrogen 4. Oxidation State increase in ox. state decrease in ox. state very good notes

redox. 🔋 oxidation state (aka oxidation number) what it is: number showing how many electrons gained/lost element type ox. state pure element (e.g. O ₂ , Cl ₂ ) 0 ion (e.g. Na ⁺ , Cl ⁻ ) same as charge O in compound usually -2 H in compound usually +1 👀 if ox. state increases → oxidation 👀 if ox. state decreases → reduction ⚔ half equations e.g. Mg → Mg² ⁺ + 2e ⁻ → oxidation Cl ₂ + 2e ⁻ → 2Cl ⁻ → reduction 💡 always balance atoms AND charge 💡 electrons must appear on correct side (left = gain, right = loss) ⚗ spotting redox in equations step 1: assign oxidation states step 2: compare before & after step 3: label what's oxidised + reduced 🧪 e.g. 2Mg + O ₂ → 2MgO Mg: 0 → +2 → oxidised O: 0 → -2 → reduced very good notes

redox. 🔥 common redox reactions: ● displacement (reactive metal kicks out less reactive one) ● combustion (burn = oxidation) ● rusting (iron oxidised) ● electrolysis (electrons move = redox party) ● acid + metal (metal oxidised, H ⁺ reduced to H ₂ gas) 🧃 electrolysis = redox event at cathode (-): reduction happens (positive ions gain e ⁻ ) at anode (+): oxidation happens (negative ions lose e ⁻ ) 💡 tip: “ PANIC ” = Positive Anode, Negative Is Cathode very good notes