Illustrating Chemical Concepts with Coin Flipping

Abstract

Three classroom demonstrations, which involve the participation of students flipping coins, are described. The half-life of a first-order chemical reaction is illustrated by standing students sitting down when they flip a “tails.” Dynamic chemical equilibrium is illustrated by students standing or sitting depending on the outcome of coin-flips. In a third demonstration, the motion of gas molecules from one bulb to another is governed by the flip of a coin, showing the improbability of all the molecules gathering in just one bulb.