Answer:
Explanation:
The equilirium system under consideration is:
A dynamic equilibrium means that it is not static: some changes are happening, but the net change is zero, and thus the changes are not observed with the naked eye.
The chemical equilbrium NH₄Cl(s) ⇄ NH₄Cl(g) shows that NH₄Cl(s) crystals, on the left side, sublimate (pass from solid state to gas state) and the NH₄Cl(g) vapors, on the right solidify (pass from gas state to solid state).
To be in equilibrium, the rate at which the crystals sublimate must equal the rate at which the vapors solidify.