ch 13 Flashcards
Solubility depends on
IMF between solute-solute, solvent-solvent, solute-solvent and the tendency towards mixing (to maximize entropy)
What are colligative properties
A property that depends on the number of partciles
-freezing pt depression
-boiling pt elevation
-osmotic pressure
What do the 3 main colligative properties depend on?
They depend on vapor pressure
the vapor pressure of a solution is
always lower than the pure solvent vapor pressure
What is osmotic pressure
the minimum pressure that must be applied to a solution to halt the flow of solvent molecules through a semipermeable membrane
If solute-solvent IMF’s are greater than or equal to in magnitude of solute solute and solvent solvent IMF’s what happens?
a solution forms
if solvent solute IMFs are less than solvent-solvent and solute-solute IMFs what happens?
a solution may form if the difference is small
The ∆H solute is always
endothermic
∆H solvent is alwaus
endothermic
∆H mixing is always
exothermic
what is the equation for the ∆H soln
∆Hsoln=∆Hsolute+∆Hsolvent+∆Mixing
if the ∆H mixing is equal to the ∆H solute+∆H solvent
the ∆Hsoln= zero
if the ∆H mixing is greater than ∆H solute+∆H solvent
them the ∆H soln<0
-heat is released, the tendency to lower energy and increase entropy drives solution formation
If ∆H mixing is less than ∆H solute+∆H solvent
then the ∆H soln>0
-heat is absorbed, entropy may still drive soln formation if the positivity is small
What is the heat of hydration
the enthalpy change when 1 mol of a gaseous state dissolves into H20 (occurs in ionic dissolving)
it is always exothermic
