Chapter 13 Flashcards
Solutions
Homogenous mixtures of two or more substances
Solute
Lesser amount
Solvent
More in content
Natural tendency
-mixing of gas is spontaneous process
-each gas acts as it is alone
-increase of disorder
-formation of solution favors entropy
Entropy
Disorder
Crystallization
opposing processes of a solution
Saturated solution
When the opposing processes is equal , the additional solute will not dissolve unless some crystallizes from the solution.
Have the solute dissolved at the temp
Unsaturated solution
When the amount of crystallization is not reached
Any amount of solute less than the max amount dissolved in the solution
Solubility
The amount of solute that can dissolve in a given amount of solvent at a given temp
Supersaturated
The solvent holds more solute than normal at a possible temp
Factors that affect solubility
Solute - solvent interactions
Temperature
Pressure for gas solutes
Will it dissolve
Solvent and solvent have similar structures
Polar and ionic more soluble in polar solvent
Nonpolar more soluble in nonpolar solvents
Temperature effect relative to solubility
Solids - temp increases solubility increases
Gases- temp increases solubility decreases
- higher mass more solubility
Solubility of gases
Solubility of gas directly proportional to its partial pressure
Sgas= Kh * Pgas
Miscible and immiscible
Mix in all proportions
Do not mix
Mass percent
= (mass of component / total mass of soln) x 100
PPM
Parts per million
10^6
=(mass of component in soln/total mass of soln) x 10^6
PPB
Parts per billion
10^9
=(mass of component in soln/total mass of soln) x 10^9
Mole fraction
=moles of component / total moles of all components
Molarity
=mol of solute / liters of the solution
Molality
=mol of the solute / Kg of solvent
Colligative properties
Depend on quantity not the identity of solute
Vapor pressure lowering
Boiling point elevation
Freezing point depression
Osmotic pressure
Electrolyte
Separates into ions when in water
Strong ones dissociate completely while weak ones dissociate very little
Nonelectrolyte
Do not dissociate to form ions
Vapor pressure
Relating to pure solutions and mixed solutions
Solvent must be greater for pressure to go up , when something is pure solvent the pressure goes up but adding a solute lowers the pressure.
Raoult’s Law
Puré solvent
Psolvent=Xsolvent * Psolvent
Solute present
DeltaPsolvent = Xsolute * Psolvent
Boiling Point elevation
Vapor pressure is lowered. Requires more tempt boiling point is increased
DeltaB = Tbsolution - Tbsolvent = iKbm
Freezing Point depression
When the boiling point is raised the freezing point is lowered
DeltaTf= Tfsolution - Tf solvent = -iKfm
Van’t Hoff factor
The ratio of moles of solute particle to moles of formula units dissolved , to find this first figure out if its an electrolyte if yes then the subscripts are the hoff factor and if not then its 1
Ósmosis
net movement of solvent molecules from solution of low to high concentration of solute across a semipermeable membrane
[] = iMRT
Isotonic
Hypotonic
Hypertonic
Same
Lower low P solvent will leave the solution at higher rate
Hyper higher p ,solvent will enter solution higher rate
Colloids
Suspensión particles larger than ions but small enough for gravity not to settle them
Tyndall effect
Colloidal suspensions can scatter rays of light
Hydrophilic
Hydrophobic
Water loving
Water fearing
