|Dissolution is favored by: |
Weak solute-solute interactions, weak solvent-solvent interactions, and strong
Consider the following rate law, rate = k [A] 3
What happens to the rate of reaction
if the concentration of A is doubled (assume the temperature remains constant)?
|The rate of reaction increases by a factor of 8.|
|Raoult’s Law is related to which colligative property?|
|List the three things (discussed in lecture) which occur in all chemical reactions.|
• Reactants are consumed
• Products are formed
• There is a transfer of energy.
The solubility of a solute is the maximum amount solute that can be dissolved in a specified quantity of solvent at a constant temperature and pressure (and result in
|The study of rates of chemical reactions and the mechanisms by which they occur. |
A physical property of a solution which depends on the number of
solute particles in a given amount of solvent, but not on the identity of the solute particle(s)
|Two liquids are miscible if one dissolves in the other in all proportions without separation. |
During lecture the dissolution process was described as consisting of three steps.
Describe each of the three steps and include if it the step is endothermic or exothermic.
1) Expand the solute: The attractive forces between solute particles must be overcome
(break the intermolecular attractive forces which exist between solute particles).
2) Expand the solvent: The attractive forces between solvent particles must be
overcome (break the intermolecular attractive forces which exist between solvent
particles). Endothermic, ΔHsolvent
3) Intermolecular interactions develop between individual solute and solvent particles
(solute particle – solvent particle attractions form). Exothermic, ΔHmix.
Describe what is meant by the phrase “like dissolves like.” Use this principle to determine if the solute will 1) dissolve in the solvent (label with the letter “D) or 2) will not
dissolve in the solvent (label with “ND”).
HCN in CCl4 ND, HCN is polar (dipole-dipole interaction)
and CCl4 is nonpolar (London interaction)
CaCl2 in H2O
D, CaCl2 is polar (i.e it is an ionic compound)
and H2O is polar (a Hydrogen bond is a
strong dipole-dipole interaction)
Like dissolves like: A solute is more likely to dissolve in a solvent if both the solute and
solvent have similar intermolecular forces.
|How does the solubility of a gas solute depend on temperature? |
|The solubility of a gas increases as the temperature decreases.|
|How does the solubility of a solid or liquid solute depend on temperature?|
The solubility of a solid or liquid generally increases as the temperature increases
(exceptions do exist).
|How does the solubility of a gas solute depend on pressure? |
|The solubility of a gas increases as the pressure increases. |
|How does the solubility of a solid or liquid solute depend on pressure.|
For all practical purposes, the solubility of a solid or liquid does not depend on
594.0 g of NaCl is dissolved in 3.780 kg of water. Determine the freezing point of
the resulting solution. Don’t forget about n (i.e. the van’t Hoff factor), kf
H2O = 1.86°C/m.