NEET Chemistry - 03 Redox, Electrochemistry and Reaction Rates

Redox reactions can feel confusing—until the electron transfers finally click. You’ll learn to drop the old “oxygen added/hydrogen removed” shortcuts and use the modern electronic idea: oxidation is loss of electrons, reduction is gain (OIL RIG). Using the classic zinc-in-copper-sulfate example, you’ll see why oxidation and reduction must happen together, how to write redox couples like Zn²⁺/Zn, and how to correctly identify oxidizing vs. reducing agents (including the common exam trap where people label them backwards). You’ll also meet frequent NEET oxidizers (permanganate, dichromate, conc. nitric acid, chlorine) and reducers (hydrogen, carbon, CO, active metals), plus why H₂O₂ and SO₂ can act either way. Next comes oxidation number: clear rules, “awkward” exceptions (peroxides, superoxides, OF₂, metal hydrides), and fractional averages in species like Fe₃O₄ and S₂O₃²⁻—including why ammonium nitrate has two different nitrogen values. From there, you’ll classify redox types, balance equations by both methods (acidic vs. basic medium), and build electrochemistry confidence: Daniell cells, cell notation, standard potentials, emf calculations, Nernst equation, and the E–ΔG–K connection. Finally, you’ll strengthen kinetics fundamentals—rate laws, order vs. molecularity, integrated equations, half-life, Arrhenius activation energy, catalysis, and collision theory—so you can spot patterns and avoid the usual traps.