SOLUBILITY
Presented by:
Naïve, Christy Marie C.
Decena, Jenny Bebs P.
Malatus, Haniyya B.
Paragamac, Roselyn A.
At the end of the presentation,
you should be able to:
1. Define solubility
2. Differentiate saturated,
unsaturated and supersaturated
solutions;
3. Determine the factors
affecting solubility;
4. Interpret Solubility curve;
5. Define rate of dissolution;
6. Determine the factors
affecting rate of dissolution.
What is Solubility?
Solubility
is the maximum amount of substance
that dissolves in a given amount of
solvent at a given temperature to
produce a saturated solution.
it is usually expressed in grams of
solute in 100 g of solvent
How is Solubility
determined?
it is when no more solute
appears to dissolve under the
existing temperature and pressure
any solution that contains less
solute than a saturated solution.
contain greater amount of
solute than a saturated solution.
Factors Affecting Solubility
1.The nature of solute & solvent
“Like dissolves like”
Polar Solute in Polar Solvent
Polar and Nonpolar Interaction
Ionic Solute in Polar Solvent
Like Dissolves like Rule for a Solid in a
Liquid
Polar Solute in Polar Solvent
Polar and Nonpolar Interaction
(an analogy with magnets)
and finally…
Ionic Solute in Polar Solvent
Like Dissolves Like Rule for a
Solid in a Liquid
Solute
Polar
Solvent
Nonpolar
Solvent
Polar
Soluble
Insoluble
Nonpolar
Insoluble
Soluble
Ionic
soluble
Insoluble
Factors Affecting Solubility
2. Temperature
Temperature
Solubility of Solid Solute
Temperature
Solubility of Gas Solute
Exercise:
Using the graph on solubility(p. 363) ,
provide what is asked:
1. Give the solubility of C12H22O11 at
20°C temperature?
2. What is the temperature of KNO3
with solubility of 60 grams per 100
grams of H2O?
Exercise:
3. Identify whether the solution is
saturated, unsaturated or supersaturated:
a. 60 g KBr in 100 g water at 60̊ᵒ C.
b. 55 g NaBr in 50 g water at 60ᵒ C.
c. 120 g KNO3 in 100 g water at 60ᵒ C.
Factors Affecting Solubility
3. Pressure
low P
high P
low c
high c
Only the gases’
concentration
increases with
pressure while
liquid and solid
solute are not
affected with
changes in
pressure.
states that the solubility
of a gas in a liquid at a
given temperature is
directly proportional to
the partial pressure of
the gas over the
solution.
William Henry (1774-1836)
To increase the
solubility of gases, what
should be done to its
pressure and temperature?
Dissolution
and
Rate of
Dissolution
is the act or process of dissolving.
The
is the measure of how fast a
substance dissolves. It is a
quantity of the solute that
will dissolve during one unit
of time.
Factors Affecting the
Rate of Dissolution
Size of the Particles
Stirring
Application of Heat
Stirring
• frequently used to speed up the
dissolution process because it
introduces fresh part of the
solvent to the solute.
• The effect of stirring is similar to
that of grinding into small
pieces – contact between the
solute and solvent is increased.
Size of the Particles
• The dissolving of a solid solute takes
place at a surface of the solid.
• Dissolving can be speeded up by
increasing the surface area thus, the
greater the surface area exposed, the
faster the solid can be dissolved.
Application of Heat
• Raising the temperature of a solvent
increases the rate at which the solute
dissolve because solvent particles
move faster.
• When solvent particles move faster,
more particles have more energy to
remove particles from the solid
solute.
Application of Heat
• Also termed as heating, it increases
the kinetic energy of the particles,
which increases the interaction
between the solute and the solvent
particles to effect dissolution.
SUMMARY
The solubility of a solute is affected
by the nature of its solute and solvent,
temperature and pressure.
Solubility of solid solute increases with
increasing temperature, while
solubility of gas solute decreases with
increasing temperature.
Solubility of solid and liquid solute
is not affected by pressure while
solubility of gas solute increases
with increasing pressure.
Rate of dissolution is influenced
by particle size, stirring, and
application of heat.
REFERENCES
o Mendoza, Esterella E.”Chemistry”.Quezon City.
Pheonix Publishing House Inc. 2003.
o www.elmhurst.edu/.../images2/171saltdissolve.gi
f for “The Nature of Solute & Solvent”
o www.worldofteaching.com for the “Pressure”
Web Images:
www.chalkbored.com for figs. on slides 6-10
www.chemland.com for figs. on slides 12,13 & 15