Chapter 13, Problem 7E

Explain why an equilibrium between ${\text{Br}}_{\text{2}}\left(\text{l}\right){\text{ and Br}}_{\text{2}}\left(\text{g}\right)$

would not be established if the container were not a closed vessel shown in Figure 13.4.

Figure 13.4.A sealed tube containing an equilibrium mixture of liquid and gaseous bromine. (credit: http://images-of-elements.com/bromine.php)