Chapter 12, Problem 12.95PAE

Equal amounts of two gases, A and B₃, are placed in an evacuated container and react to form AB and B₂.

   $\text{A}\left(g\right)+{\text{B}}_3\left(g\right)\rightleftarrows \text{AB}\left(g\right)+{\text{B}}_2\left(g\right)$

The molecular scale diagram represents the relative amounts of each substance present once equilibrium is reached.

Which of the following graphs best describes the progress of the reaction as it proceeds to equilibrium? Explain why the graph you chose must be the correct one.