General Chemistry A: Chapter 14 Solutions and Their Physical Properties Lecture Notes

Introduction
-a solution is a homogenous mixture where the components
are uniformly intermingled
- the particles have the sizes of atoms, ions, and small
molecules
- they can exist in an state. Solid, liquid, gas.
- different solids have different solubilities which vary w/
temp




exception
←




In General, T Temp means ↑
solubility


- consider a solution made by stirring 2.0g of solid kclo3 into
a container containing 100. G of water at 30.c.
- what is the solute? Kclo3
- solvent? H2o
-solution? Kclo3 solution
- this is an unsaturated solution

- if another 10.g of solid kclo3 is added into the above
solution at the same temp, eve after stirring f or a length
of time, some solid remains at the bottom.
- is the resulting solution saturated, unsaturated or
supersaturated? Saturated

, - the mixture is then heated to 40.c and solid disappears.
- is the resulting solution saturated, unsaturated or
supersaturated? Unsaturated, b/c the max you could put
in is about 13g. We only have 12 so far

- the solution is then cooled down slowly to 30.c. Do you
expect any solid precipites out of the solution?
-yes

- if there is solid settle out of the solution is the solution
saturated, supersaturated or unsaturated?
- Saturated.

- if there is no solid settle out of the solution, is the
solution saturated, unsaturated or supersaturated?
Supersaturated. (It is also unstable bc any disturbance can
make excess settle up)



Review of concentration unit
Mass percent, volume percent, and mass/volume percent solute

Mass %: mass of solution
—————————. X 100%
mass of solution

= mass of solute
—————————— X 100
mass of solute + mass of solvent