1. Calculations Involving Solutions
UNIT VIII PPT #2
Calculations Involving Solutions

2. IX.6 CALCULATING THE CONCENTRATIONS OF IONS IN SOLUTIONS
REVIEW:
M = [ ] = molarity = C = n = mol = molar concentration
V L

3. IX.6 CALCULATING THE CONCENTRATIONS OF IONS IN SOLUTIONS
1.What is the concentration of Cl ions in 0.350M solution of HCl?
HCl → H+ + Cl-
[Cl-] = mol HCl x 1 mol Cl- = M Cl-
L mol HCL
2. What is the concentration of H= ions in a 1.40 M solution of H2SO4?
H2SO4 → 2H+ + SO42-
[H+] = 1.40M H2SO4 x 2 mol H = 2.80 M H+
L mol H2SO4

4. IX.6 CALCULATING THE CONCENTRATIONS OF IONS IN SOLUTIONS
Example #1: a. What is the molar concentration of the sodium ions in 0.25M NaOH(aq)? NaOH → Na+ + OH- [Na+] = 0.25 mol NaOH x 1 mol Na+ = 0.25 M 1L 1 mol NaOH b. What is the molar concentration of the chloride ions in 0.45 M AlCl3(aq)? AlCl3 → Al3+ + 3Cl- [Cl-] = 0.45 mol AlCl3 x 3 mol Cl- = 1.35 M 1L 1 mol AlCl3

5. IX.6 CALCULATING THE CONCENTRATIONS OF IONS IN SOLUTIONS
Example #2 What is the chloride ion concentration when 20.0 g of BaCl2(s) is dissolved and diluted to 800.mL? BaCl2 → Ba2+ + 2Cl- 1. # mol = g x 1 mol = mol g 2. C=n/V = mol/0.800L = 0.12 M 3. [Cl-] = 0.12 mol x 2 mol Cl- = 0.24 M 1L 1 mol BaCl2

6. IX.6 CALCULATING THE CONCENTRATIONS OF IONS IN SOLUTIONS
REVIEW:
C1V1 = C2V2
Cdil x Vdil = Cconc x Vconc

7. IX.6 CALCULATING THE CONCENTRATIONS OF IONS IN SOLUTIONS
Example #3
A solution is made by mixing mL of M BaSO4 and 80.0 mL of M MgF2. What is the concentration of each ionic species in the final solution?
Steps:
Balanced dissociation reactions
Dilutions to find final Molarity of both
Set up concentrations with dissociation equation
ID species (and multiply)

8. IX.6 CALCULATING THE CONCENTRATIONS OF IONS IN SOLUTIONS
Example #4
A solution is made by mixing 50.0 mL of M BaCl2 and mL of M NaCl. What is the concentration of each ionic species in the final solution?
Hebden p. 212 # 30-38