Mod 5 Solubility Equilibria Flashcards
Describe the processes involved in the dissolution of ionic compounds in water
It is only when the solution is saturated, that the dissolution reaction is equilibrium.
Water is a polar molecule, where it is slightly positive at the hydrogen ends and slightly negative on the oxygen end. These charged ends of the molecule will attract the opposite charge in the ionic compound.
However, not all ionic compounds are soluble in water or are partially soluble in water. This is because the ion dipole forces between ions and the polar molecule is not strong enough to break the ionic bonds that holds the ions together in the lattice
What is a saturated solution?
A solution in which the maximum amount of solvent has been dissolved. Any more solute added will sit as crystals on the bottom of the container.
What is the solubility of a substance?
Max amount of solute that dissolves in a specific amount of solvent at a particular temp.
What is a solute?
Substance that is dissolved in a solvent, forming a solution
What is a solvent?
Something that dissolves
What is the difference between molar solubility and solubility?
Solubility is typically the mass of solute/volume of saturated solution, molar solubility is typically number of moles/ volume (L)
What is density(p)?
Mass of substance (m)/ volume of substance (v)
How to calculat parts per million?
mass of substance (in mg)/ volume of substance ( in kg)
How to calculatee parts per billion?
Mass of substance (in micrograms)/ volume of substance (in kg)
How to calculate percentage by mass?
g/100g = %w/w
How to calculat percentage by volume
mL/100mL = %v/v
What is the formula of solubility product constant (ksp)?
It is the equilibrium constant for the dissolution process of an ionic solid that dissociates completely in solution
What is the geeneral equation for ksp?
AaBb (s) ⇌ aA x+ (aq)+ bB y- (aq)
What is the formula for Ksp?
[A^x+]^a [b^y-]^b
What happens if value of Ksp is small?
Indicates a highly insoluble solution, as there are less dissociated ions than there are solids.
What happens if value of Ksp is big?
Indicates a highly soluble solution, as there are more dissociated ions than there are solids.
What is Qsp?
Essentially same as Ksp but does not have to be in equilibrium
What happens if Qsp > Ksp
Therefore, system attempts to reach equilbrium through favouring the reaction which reduces aqueous ions –> favouring reverse reaction –> formation of precipitate