Chemical dissolution is when a solute contacts a solvent and forms a solution by dissolving. Dissolution is the reverse of the precipitation process, and the two processes form a dynamic equilibrium.
The precipitation of a solid form or the evolution of gas occurs when evaporation or another process removes the solvent from the solution. When the precipitation or gas evolution begins, the maximum solute concentration is determined by the solute concentration at the beginning of the process. Both the dissolution of solids and the dissolution of gases occur as a surface process, which means the processes may not take place uniformly with certain forms such as solid salts.