If you have solids that need to be dissolved, what can you do to speed the process up?

2 Answers
Jun 22, 2018

Heat the solvent...


...in a heated liquid, the individual molecules are moving around more vigorously, which enhances their ability to dissolve the solid.

Jun 22, 2018

There is a variety of things that could be tried....


Heating up the solvent is one possibility, provided the solvent is not too low boiling point, otherwise you may end up losing it all as vapour (and in the case of organic solvents, need to be mindful of heating method, due to flash point risks).

Other ways include:

(a) break the solid into smaller sized pieces - smaller pieces of the same quantity of solid will have a greater surface areea to volume ratio, and as solvation is initiated on the surfaces of solids, it means that the process takes place faster.

(b) increase the rate of stirring, this ensures that maximum amounts of surface are brought into contact with the solvent per unit time, thereby speeding up solvation.

(c) if the solid is one that needs to be pulled apart in order to be dissolved, for example, synthetic rubber being dissolved in oil, increase the rate of shear - use something like a Silverson mixer head instead of a paddle stirrer. This will ensure that bulk pieces are pulled apart faster and solvent/solute interactions maximised.