A New Road, Not a Bigger Push

You'll learnhow a catalyst opens a lower-barrier path without changing the start energy, end energy, or equilibrium.

A bottle of hydrogen peroxide sits on a shelf for a year and does nothing. Drop in a speck of iodide and it foams over the bench in seconds. Nothing about the products changed, and nothing about the energy released changed. Twelve short steps; press Next for each one.

12 STEPS · 6 QUICK CHECKS · 2 H₂O₂ → 2 H₂O + O₂ · E_a 75 → 56 kJ/mol · v4

two roads between the same two places

Before you start

What you're looking at

The energy profile for hydrogen peroxide falling apart, and the hill that keeps the bottle on the shelf.

The question

A speck of iodide makes it foam over in seconds. What did the iodide actually change?

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