Solubility Factors

what is the common ion effect

the decrease in solubility of an ionic compound when a salt containing on of its constituent ions is added tot he solution (same ion)

how does Le Chatelier’s principle explain the common ion effect

adding a product (ion) shifts the equilibrium to the left, favoring the solid (precipitate) form

when does decreasing pH (adding acid) increase solubility

when the solid contains a basic anion (conjugate base of a weak acid)

changing the pH doesn’t affect the solubility of what ions?

neutral because they do not react with H+

how does complex ion formation affect solubility?

increases solubility by removing the metal cation from the initial solubility equilibrium, shifting the reaction to the right

what is a complex ion formation

when a lewis base is added/bonded to a central metal cation

if Q=Ksp

saturated solution

at equilibrium

if Q>Ksp

supersaturated solution

precipitation of a solid will occur

if Q<Ksp

unsaturated solution

no precipitation, solid will dissolve

equation to determine ion concentration after solutions are combined

[ion]= (mol ion)/(total solution volume)

if ΔS>0

spontaneous process

if ΔS<0

non-spontaneous process

if ΔS=0

equilibrium

exothermic reaction

ΔH is +

system → surroundings

releasing heat

ΔS is +

endothermic reaction

ΔH is -

surroundings → system

absorbing heat

ΔS is -