Chapter 13: Properties of Solutions
Homogeneous mixtures are called _____________________.
Give an example of a:
a) solid solution
b) gas solution
c) liquid solution
What are the two parts of a solution called?
What type of solution contains water as the solvent?
The Solution Process
What two factors does the ability of a substance to form solutions depend on?
1)
2)
The Natural Tendency Toward Mixing
How is the mixing of gases a spontaneous process?
Define entropy. How does entropy change when a solution is formed?
How does the state of matter change the mixing process of solutions?
The Effect of IMF on Solution Formation
Describe the three kinds of intermolecular interactions involved in solution formation.
1) Solute-solute
2) Solvent-solvent
3) Solvent-solute
Describe how the extent to which one substance is able to dissolve in another depends on the relative
magnitudes of the previous three types of interactions.
Define:
solvation-
hydrationEnergetics of Solution Formation
Solution processes are typically accompanied by changes in enthalpy.
TRUE
or
FALSE
Illustrate how NaCℓ would look as it was forming a solution.
What is the formula for the overall enthalpy change, ∆Hsoln, for a solution?
Tell if the following are endothermic or exothermic:
1) ∆Hsolute
2) ∆Hsolvent
Is the formation of a solution exothermic or endothermic?
What types of processes proceed spontaneously?
What occurs if ∆Hsoln is too endothermic?
What needs to happen in order for solutions to form?
Why do ionic solutes not dissolve in nonpolar solvents?
3) ∆Hmix
Why does a polar liquid solute not dissolve in a nonpolar liquid solvent?
Saturated Solutions and Solubility
Define crystallization.
What does the half arrow represent as in the equation on the bottom of page 518?
When does dynamic equilibrium become established?
Define:
saturated-
solubility-
*How many grams of sodium chloride can be dissolved in 1 liter of water at 0°C?
unsaturated-
supersaturated-
*What is added to form a supersaturated solution?
Factors Affecting Solubility
Solute-Solvent Interactions
Does solubility of gases in water increase or decrease as the molecular weight increases? Explain.
When is the solubility the greatest if molecular weights and polarity are similar?
Why do polar molecules tend to dissolve only other polar molecules?
Define and give an example of each:
miscible-
immiscible-
What are alcohols?
How does solubility inn water change with increasing carbons in an alcohol? Explain.
What phrase is used to describe solubility of certain substances in one another? Explain.
Sample Exercise 13.1
Predict whether each of the following substances is more likely to dissolve in the nonpolar solvent carbon
tetrachloride (CCℓ4) or in water: C7H16, Na2SO4, HCℓ, and I2.
Practice Exercise
Arrange the following substances in order of increasing solubility in water:
1)
3)
2)
4)
Pressure Effects
How is the solubility of a gas affected by pressure?
When is equilibrium established?
Henry’s Law: Sg = kPg
What does each variable represent and what are the units for each variable?
What is another word for solubility?
Sample Exercise 13.2
Calculate the concentration of CO2 in a soft drink that is bottled with a partial pressure of CO2 of 4.0atm over
the liquid at 25°C. The Henry’s Law constant for CO2 in water at this temperature is 3.4 x 10-2 mol/Latm.
Practice Exercise
Calculate the concentration of CO2 in a soft drink after the bottle is opened and equilibrates at 25°C under a
CO2 partial pressure of 3.0 x 10-4atm.
Temperature Effects
Is solubility of most solids directly or indirectly proportional to temperature? Give an example.
Is solubility of gases directly or indirectly proportional to temperature? Give an example.
Expressing Solution Concentration
Define:
dilute-
concentrated-