Question

Does dissolution and crystallization always take place simultaneously?

Also does crystallization also occur in unsaturated solution but its rate is less than rate of dissolution or is rate of crystallization 0?

Answer 1

Dissolution and crystallization may not always occur simultaneously. These processes equilibrate in a saturated solution but in an unsaturated solution, crystallization occurs at a slower rate than dissolution.

Step-by-step explanation:

Dissolution and crystallization do not necessarily occur simultaneously. In the context of a saturated solution, these two processes do occur at the same time at a dynamic equilibrium, where the rate of dissolution is equal to the rate of crystallization. However, in an unsaturated solution, the rate of crystallization is not necessarily zero, but rather, less than the rate of dissolution until the solution becomes saturated, at which point both rates equalize.

Crystallization can also occur in an unsaturated solution when solute particles collide with the surface of existing solute particles; however, this occurs at a slower rate compared to a saturated solution. The solubility of substances can also be affected by factors such as temperature, where typically, the solubility increases as the temperature rises.