Calculating Solubility

Unit III: Solubility Equilibrium

Calculating SolubilityExample 1

It is experimentally found that 1L of saturated AgBrO3 (aq) contains 1.96 g of AgBrO3. What is the molar solubility of AgBrO3?

Calculating SolubilityExample 2

The molar solubility of PbI2 is 1.37 x 10-3 M. Express this value in grams per litre.

Calculating SolubilityExample 3

It is experimentally found that 250 mL of saturated CaCl2 contain 18.6 g of CaCl2. What is the solubility of CaCl2?

Calculating SolubilityExample 4 (Hebden p. 78 #15)

A chemistry student was assigned the task of determining the solubility of potassium chloride, KCl. She added an excess of solid KCl to water, stirred, and let the solution sit overnight. The next day, she pipetted a 25.00 mL portion of the saturated solution into a pre-weighed evaporating dish, determined the combined mass, carefully boiled off the water present, allowed the residue to cool and re-determined the mass of the evaporating dish and residue. The data obtained is given below.

Calculating SolubilityTemperature of solution = 22.5ºCMass of evaporating dish = 54.87 gMass of solution and evaporating dish = 84.84 gMass of residue and evaporating dish = 62.59 g

Calculate:a)The mass of 25.00 mL of the solution.b)The mass of KCl in 25.00 mL of solution.c) The mass of water in 25.00 mL of solution.d)The mass of KCl which can dissolve in 100.0 g of

water at 22.5ºC. e)The molar solubility of KCl, expressed in moles of KCl

per litre of solution.

Calculating Ion ConcentrationsExample 5

Calculate the concentration of all ions in each of the following solutions.

a) 2.5 M CaCl2

Calculating Ion ConcentrationsExample 5 (continued)

Calculate the concentration of all ions in each of the following solutions.

b) 0.68 M Al2(SO4)3

Calculating Ion ConcentrationsExample 5 (continued)

Calculate the concentration of all ions in each of the following solutions.

c) 8.0 g of KBr in 500 mL

Calculating Ion ConcentrationsIt will also be necessary to take into

account the dilution that occurs when solutions of ions are mixed with water or each other.

C1V1 = C2V2

Calculating Ion ConcentrationsExample 6Calculate the concentration of all the ions

present when: a) 150 mL of water is added to 125 ml of

0.25 M Cl-

Calculating Ion ConcentrationsExample 6 (continued)Calculate the concentration of all the ions

present when: b) 25.0 mL of 0.200 M Ag+ is added to 55.0

mL of 0.500 M NO3-

Calculating Ion ConcentrationsExample 6 (continued)Calculate the concentration of all the ions

present when: c) 15.0 mL of 0.75 M MgCl2 is mixed with

30.0 mL of 0.60 M CaBr2

Calculating Ion ConcentrationsExample 6 (continued)Calculate the concentration of all the ions

present when: d) 65.0 mL of 0.450 M AgNO3 is mixed with

80.0 mL of 0.900 M Ba(NO3)2

Solubility Graph

Assignment