When iodine crystals sublimate into iodine gas within a sealed flask, the
system will eventually reach a heterogeneous equilibrium.
Step-by-step explanation:
Sublimation is the process in which substances of solids gets converted into gases. In this process of sublimation there is no occurrence of intermediate state called liquid form.
In Iodine sublimation the iodine crystals are placed in a beaker and gets heated. During this heating the crystal form of iodine is converted to gas state without interference of liquid form. This is called Iodine sublimation.
This conversion of one form of reactants to other form of products comes under heterogeneous equilibrium.