Ksp

Question 1

What is solubility

Answer 1

solubility is the max amt of solute that can be added to 1dm3 of solvent to form a saturated solution at a fixed temperature

Question 2

what is ksp

Answer 2

ksp is the ionic product of a sparingly soluble salt’s constituent ions’ concentrations in a saturated solution raised to their appropriate powers at a given temperature. (the saturated soln is j abt to ppt)

Question 3

limitations to ksp concept

Answer 3

cannot be used for soluble salts like NaCl
value is very small for sparingly soluble salts
it only varies with temperature
cannot immediately be used to determine solubility (high ksp does not = high solubility) unless the ratio of cations to anions in solution is the same (e.g. AgCl and BaCO3) basically they have same no. of ions then can compare ksp to tell which one more soluble if not more

Question 4

ionic product

Answer 4

has the same expression as ksp
it is the product of a salt’s constituent ions’ conc. raised to appropriate powers at any instance in a solution at a given temperature.

Question 5

to predict solubility…

Answer 5

if IP > Ksp ppt will occur till IP=Ksp (no ppt formed)
if P=Ksp no ppt in saturated solution (trace ppt formed)
if P<Ksp no ppt in dilute solution (ppt formed till eqm is attained between saturated solution and precipitate)

Question 6

selective ppt

Answer 6

to use a reagent to ppt one or few ions but not all

Question 7

factors affecting solubility

Answer 7

common ion effect
pH
complex ion formation

Question 8

Common ion effect is when the solubility of a salt AxBy is reduced by the presence of Ay+ or Bx- from a second sourcse

Answer 8

is when the solubility of a salt AxBy is reduced by the presence of Ay+ or Bx- from a second source

can use Le chatelier of IP and Ksp to determine change in solubility

Question 9

pH

Answer 9

when the addition of H+ or OH- affects the concentration of one of the salt’s constituent ions by reacting with it resulting in shift in POE

Question 10

complex ions

Answer 10

increase solubility of salts
if there is an acid/base write out their dissociation first and then whichever ion they would react with

Question 11

precipitates of halides

Answer 11

Ag+ reacts with halide ion to form AgX
(ppt)
Ag+ reacts with excess with NH3 forms complex ion which is [Ag(NH3)2]+

solubility of halides
AgCl>AgBr>AgI
only agcl dissolves in excess NH3