Guided Notes
Saturated Solutions and Solubility/Factors Affecting
Solubility
A solution is __________ if the maximum amount of solute is present that
will dissolve in a given amount of solvent at that temperature. If we
dissolve less solute than needed to form a saturated solution, the
solution is ________________.
Sometimes it is possible to form solutions that contain a greater amount of
solute than is needed to form a saturated solution. Such solutions are
________________.
In general, the stronger the attractions are between solute and solvent
molecules, the _________________ the solubility.
Pairs of liquids that mix in all proportions are _____________; those that
do not dissolve in one another are immiscible.
The presence of OH groups capable of _____________ bonding with water
enhances the solubility of organic molecules.
Which of the following will dissolve in water:
C7H16 Na2SO4 HCl
I2
Remember to use differences in electronegativity if you need to assess if a
molecule is nonpolar, polar, or ionic.
Less than 0.5 nonpolar
0.5 – 1.7 polar
greater than 1.7 ionic
The solubilities of solids and liquids are not greatly affected by pressure,
whereas the solubility of a gas in any solvent is increased as the pressure
over the solvent __________________.
The relationship between pressure and the solubility of a gas is expressed
by a simple equation known as___________________;
Sg = kPg
Calculate the concentration of CO2 in a soft drink after the bottle is opened
and equilibrates at 25 oC under a CO2 partial pressure of 3.0 x 10-4 atm.
The Henry’s law constant for water at this temperature is 3.1 x 10-2 mol/Latm.
The solubility of most solid solutes in water _____________ as the
temperature of the solution increases.
The solubility of gases in water ________________ with increasing
temperature.
Ways of Expressing Concentration
We will examine four ways to express concentration in quantitative terms:
Mass percentage, mole fraction, molarity, and molality
1. Mass percentage
Mass % of component= mass of component in solution x 100
Total mass of solution
A commercial bleaching solution contains 3.62 mass% sodium
hypochlorite, NaOCl. What is the mass of NaOCl in a bottle containing
2.50 kg of bleaching solution?
2. Mole Fraction
Mole fraction = moles of component
total moles of all components
The symbol X is commonly used for mole fraction, with a subscript to
indicate the component of interest. For example, the mole fraction of NaCl
in a solution of NaCl is represented as XNaCl. Mole fractions have no units.
An aqueous solution of hydrochloric acid contains 36% HCl by mass.
Calculate the mole fraction of HCl in the solution.
3. Molarity
Molarity = moles of solute
liters of solution
What is the molarity of a solution made by diluting 35.0 mL of 9.00 M H2
SO4 diluted to 0.500 L?
4. Molality
Molality = = moles of solute
kilograms of solvent
A solution containing equal masses of glycerol(C3H8O3) and water has a
density of 1.10 g/mL. Calculate the molality of glycerol.