An instant cold pack purchased in a pharmacy contains a packet of solid ammonium nitrate surrounded by a pouch of water. When the packet of NH4NO3 is broken, the solid dissolves in water and cooling of the mixture occurs because the solution process for NH4NO3 is endothermic. Explain, in terms of what happens to the molecules and ions, why this mixing occurs spontaneously.
A. In solution, the ions NH4+ and NO3- are highly ordered throughout the solvent.
B. In the solid, the ions in NH4NO3 are highly ordered.
C. In solution, the ions NH4+ and NO3- are randomly distributed throughout the solvent.
D. The increase in randomness makes the process spontaneous.
E. The decrease in randomness makes the process spontaneous.