Topic: Solubility and Table G
Do Now: label as soluble and insoluble
1. CH4
2. AgCl
3. C12H22O11
4. NaNO3
5. KOH
Review: Next 3 slides
Water is often used as a solvent
Not everything dissolves in water
•
•
•
•
Soluble = dissolves in water = aq
Insoluble = doesn’t dissolve in water
Miscible = 2 liquids that dissolve
Immiscible = 2 liquids that don’t dissolve
How can you tell….?!!!??
• Like Dissolve Like
– Water is polar, so most polar compounds will dissolve in
water
• Things that dissolve in water
– Soluble ionic compounds – use Table F
– Acids - start with H except H2O H2O2
• ex HCl
– Bases - metal + OH and NH3
• ex. NaOH
– Polar covalent molecules
• Remember polar = asymmetrical = poles
nonpolar = symmetrical = no poles
Determining if an ionic compound is
soluble (aq) or NOT
• LOOK AT TABLE F
– LiOH
– Cu(NO3)2
– AgCl2
– MgS
– NaS2
– KOH
– aq
– aq
– Insoluble = s
– Insoluble = s
– aq
– aq
Solubility = the max amount of solute
that can be dissolved in a solvent
• Factors that affect the rate a species dissolves
– Increasing temperature
– stirring (agitation)
– Crushing (smaller particle size)
Solubility
• Many solids and gases dissolve in
water
• As you increase the temperature,
you can dissolve more solid
• Does this work the same with gas?
• NOT the same for gases – as you increase temp,
gas molecules KE ?
• To get gases dissolve, decrease temperature and
increase pressure
DEMO VIDEO
Summary: Factors Affecting Solubility
• Nature of the solvent and the solute:
LIKE DISSOLVES LIKE
• Temperature
• Pressure (for systems with gases)
Solubility curves
show the
relationship
between solubility
and temperature.
• Can you guess
which of these
compounds are
gases?! How do
you know?!
Reading a solubility curve!
Table G
tells you the
max amount
of solute you
can dissolve
in 100 g of
H2O at a
given
temperature
How much H2O
is required to just
dissolve 100 g
NaNO3 at 20C?
89 g
Problem:
How much KCl
will dissolve in
100g of water at
50C?
42 g
• On the line – saturated (full, cannot hold any more
solute
• Below the line – unsaturated (can hold more
solute)
• Above the line – supersaturated (holding more
solute then it should – very unstable)
Unsaturated solution
Saturated Solution
Supersaturated Solution
(this picture is showing the addition of 100 g of
glucose to 100ml of water at 250C) Note: at 250C, only
91g of glucose will dissolve in 100 ml of water
Let’s see
what
happens