Representations of Equilibrium

Equilibrium isn't a finish line where the reaction stops. It's a container where the forward reaction and the reverse reaction both keep firing, at equal rates, forever. A drawing of that container is a snapshot of real particles that exist at that moment, so it has to show some reactant molecules and some product molecules together, never just one kind. The mix doesn't change over time once equilibrium is reached, even though individual particles keep converting back and forth.

The ratio of dots in the drawing is the whole point: it encodes K. A reaction with a large K (say K = 1000) sits far toward products, so a correct drawing shows mostly product particles with only a few reactants scattered in. A reaction with a small K (say K = 0.001) does the opposite: mostly reactants, with a few product particles mixed in. There is no rule that the numbers should ever come out equal; equal numbers would only happen to match one specific K value, not equilibrium in general. A series of drawings taken over time, before equilibrium is reached, shows the particle counts shifting steadily until they stop changing from one frame to the next. That stopping point is equilibrium.

This connects straight to Le Chatelier's idea: if you draw a container at equilibrium and then inject more reactant particles, the next drawing right after injection just shows more reactant dots added in, with the product count unchanged. Only after time passes does the picture shift again, with some of that extra reactant converting to product until the ratio matches K once more.