Flat, Not Crossed

You'll learnhow to spot equilibrium on a graph, and read one flask off all three pictures.

Seal a gas in a flask and it settles. AP Chemistry then shows you that one flask three ways — the equation, a drawing of the particles, and a graph — and the graph is where most people misread it, because the eye lands on the wrong feature. Twelve short steps; press Next for each one.

12 STEPS · 6 QUICK CHECKS · N₂O₄(g) ⇌ 2 NO₂(g) · K_c = [NO₂]²/[N₂O₄] · v4

one flask · the equation, the particles and the graph

Before you start

What you're looking at

A sealed flask of N2O4, drawn as particles and plotted as two curves against time.

The question

Which feature of the graph tells you the flask has reached equilibrium?

Step 1 / 12