SM-Educate Chemistry

  Hess's Law: Why You Can Add and Subtract Reactions Like Equations Here's where most students get stuck with Hess's Law: not the concept itself, but trusting it enough to actually use it in an exam. The rule sounds almost too convenient — add up two reactions, and somehow you know the enthalpy of a third one you never even ran? It feels like a trick. It isn't. Once you see why it works, you stop memorizing it and start just... using it. What Hess's Law Actually Says The enthalpy change of a reaction is the same no matter how many steps you take to get there — one giant leap or five smaller ones, the total energy change is identical. That's it. That's the whole law. Why This Isn't Magic — It's Just Physics Enthalpy is a state function . That word gets thrown around a lot without explanation, so here's the plain version: a state function only cares about where you started and where you ended up — not the path you took. Think of it like al...

Why Do Bonds Break? | SM-EDUCATE Chemistry 🧪 SM-EDUCATE CHEMISTRY June 06, 2026 Why do bonds break? Rethinking Activation Energy Deep Chemistry Deep chemistry · Conceptual frontiers · Demanding insights 📤 SHARE Physical Chemistry Chemical Dynamics Activation Energy Transition State Theory Quantum Tunneling Entropy in Chemistry If you’ve taken general chemistry, you know the textbook story: “Molecules need a minimum amount of energy—the activation energy (\(E_a\))—to break bonds and react. Heat provides that energy. The higher the temperature, the faster the reaction.” Neat. Clean. And… incomplete . That textbook definition isn’t wrong . But it hides almost everything interesting about what actually happens the instant a bond decides to let go. Let’s step beyond the Arrhenius plot and ask the messy, real question: Why do bonds break when t...