Aqueous Systems 3.6

Solubility

Solubility is measured in

Ks
the constant of the equilibrium of a saturated solution of sparingly soluble compounds
has no units

Saturated solution

D

Calculating Ks, given solubility of a 1:1
Of 1 mol of A+ and 1 mol of B-

Calculating Ks, given solubility of a 2:1
Of 1 mol of A+ and 2 mol of B- or vice versa

Calculating s, given Ks of a 2:1
Of 1 mol of A+ and 2 mol of B- or vice versa

Calculating s, given Ks of a 1:1
Of 1 mol of A+ and 1 mol of B- or vice versa

Calculating ion conc given Ks
steps

Calculating Ks from solubility given in gL-1 (grams per litre)
steps

gL-1 convert to mol L-1

Calculating moles

calculating concentration

calculating Ks given mass and volume
steps

Common ion effect

Reduced solubility

Increased solubility

Calculating solubility in solutions with common ion

Common ion calculations when solutions are mixed
steps

Ionic product
apples to solution of any solute concentration

Predicting Precipitation

Determining whether a ppt will form or not
steps

calculating ion conc to form a ppt
steps

Predicting ppt the solutions are mixed when two solutions are mixed the ion conc is diluted
steps

Predicting ppt when grams of solute (solid) are added
steps

Calculating minimum quantity required for a ppt to form
steps
given the question "What is the minimum mass?"

Factors affecting solubility

increased temperature, increases solubility

decreased temperature, decreases solubility

Common ions present, reduces solubility

added complex ions to metal cation, solubility increases

important complex ions

important complex ions

low pH with high conc of H3O+ ions, increases solubilty

high pH with high conc of OH- ions, increases solubilty

Comparing the solubility of acidic and alkaline conditions (acid and base)
explaining why something dissolves better in a solution with a very low pH and a very high pH

Strong Acids

Weak acids

Strong bases

Weak bases

Acidic salts

Basic salts

Calculating pH of a acidic salt in solution

Finding Ka (acid dissociation constant )

Conjugate acid/base pair examples

pKa and its formulars

pKa is used to give the measure of the strength of an acid

Calculations of Weak Acids
making assumptions

pH of a weak acid given Ka
steps

Finding pH given [H3O+]

finding [H3O+] given pH

Concentration of a weak acid given pH
steps

Amphiprotic substances

Ionic product of water Kw

Kw formulars

Finding Kb (base dissociation constant)

Calculating Kb given Ka

Calculating Kb given pKa

Calculations of Weak Bases
making assumptions

pH of a weak base given Ka
steps

calculating concentration of a weak base given pH

Calculating pH of a basic salt in solution

Relative concentration of species

Conductivity of soultions