CHM-5 Solution Chemistry Flashcards
How are solutions made?
Breakdown of intermolecular forces between solvents (Endothermic).
Reformation of intermolecular forces between solute and solvent (Exothermic).
What is enthalpy?
A measure of the total energy change in endothermic and exothermic reactions.
If the over all reaction (Enthalpy) is exothermic…
Intermolecular bonds are more stable and a solution is formed.
Why does the formation of a solution always result in an increase of entropy or disorder?
The energy has a tendancy to disperse
What is entropy?
A lack of order or predictability
What are colligative properties?
Properties that depend only on the number of particles present and not the kind of particle.
What is the Van’t Hoff Factor (i)?
The ratio of moles of particles/ions in a solution to the moles of all undissociated formula units (or molecules) within a solution.
What is the Van’t Hoff Factor for non-ionic solutions?
1 - Because the particles are undissociated.
How is the Van’t Hoff Factor determined?
By the number of ions dissociated in the solution.
E.g:
NaCl = 2
CaCl2 = 3
When a nonvolatile solute is disolved in a solvent…
The vapor pressure of the solution is lower that the pure solvent.
What is Raoult’s Law?
The lowering of the vapor pressure of the solvent is proportional to the mole fraction of solvent and independent of the chemical nature of the solute.
What is a freezing point depression?
When a solute (Salt) is added to a solvent (Water), the freezing point is is lower.
What is a boiling point elevation?
When a solute is added to a solvent, making the solvent have a higher boiling point.
During osmosis, at what point does the solvent stop passing through the membrane?
Until a sufficient hydrostatic pressure develops.
What is an electrolyte?
A solute that dissolves in water to give a solution that contains ions, thus conducting electricity.
If a solid is dissociated into seperate ions surrounded by water, it has been…
Hydrated
If dissociation is incomplete and reversible, you get….
a weak electrolyte
If dissociation doesn’t occur, you have…
a nonelectrolyte, E.g Glucose C6H12O6 doesn’t split
Solubility of a solute is determined by…
the maximum amount of solute that can be dissolved in an appropriate solvent.
What is K\/sp?
Solubility Product - An overall equilibrium constant
A lower K\/sp means a solute is less soluble.
What is the common ion effect?
If there is an excess of one ion over the other, the concentration of the other ion is supressed.
