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February 8th, 2017
● How do we prepare a supersaturated solution?
○ Many materials are more soluble at higher temperatures
○ So, first prepare a solution at a higher temperature so more of the solute
○ Cool it down carefully
■ What should happen?
● Should form a precipitate and have extra solute
■ What actually happens
● If it is carefully cooled down properly, you won’t have any
● So therefore it will have more solute than it should (that’s
why they call it supersaturated)
○ Sometimes it can cool down without the solute crystallizing. When it does,
it then contains more solute than it would at the lower temperature.
○ They are not very stable, so it doesn’t take much to upset this and ruin the
○ By adding a seed crystal is will take away the excess solute and the
excess solute will come out of the solution
■ Also provides nucleation sites
■ Solution that still remains after this process is saturated
○ Figure 13.11
■ Just excess solute comes out not ALL of the solute
● Liquids dissolving in liquids
○ Miscible: term used to describe two liquids that are SOLUBLE in each
other to an appreciable extent
○ Immiscible: term used to describe two liquids that are NOT soluble in each
other to an appreciable extent.
■ Liquids that are immiscible form in layers
■ Figure 13.4
● You can see a clear difference where the layers are in the
tube, there is a blue liquid layer lying on top of the clear
● Like Dissolves Like
○ AKA similiar dissolves similar
○ General rules/guidelines (there are exceptions)