1. Reactions in Aqueous Solutions II: Calculations
Chapter 11
Reactions in Aqueous Solutions II: Calculations 1 1 1 1 1 1 1 1

2. Calculations Involving Molarity
Example 11-1: If mL of 1.00 M NaOH and mL of M H2SO4 solutions are mixed, what will the concentration of the resulting solution be?
What is the balanced reaction? It is very important that we always use a balanced chemical reaction when doing stoichiometric calculations. 2 2 2 2 3 3 3 3

3. Calculations Involving Molarity
Reaction
Ratio:
2 mmol
1 mmol
Before
Reaction:
100 mmol
50 mmol
0 mmol
After 3 3 3 3 4 4 4 4

4. Calculations Involving Molarity
What is the total volume of solution?
100.0 mL mL = mL
What is the sodium sulfate amount, in mmol?
50.0 mmol
What is the molarity of the solution?
M = 50 mmol/200 mL = M Na2SO4 4 4 4 4 5 5 5 5

5. Calculations Involving Molarity
Example 11-2: If mL of 1.00 M KOH and mL of M H2SO4 solutions are mixed, what will be the concentration of KOH and K2SO4 in the resulting solution?
What is the balanced reaction? 5 5 5 6 6 6 6

6. Calculations Involving Molarity
Reaction
Ratio:
2 mmol
1 mmol
Before
Reaction:
130 mmol
50 mmol
0 mmol
After
30 mmol
100 mmol 6 6 6 7 7 7 7

7. Calculations Involving Molarity
What is the total volume of solution?
130.0 mL mL = mL
What are the potassium hydroxide and potassium sulfate amounts?
30.0 mmol & 50.0 mmol
What is the molarity of the solution?
M = 30.0 mmol/230.0 mL = M KOH
M = 50.0 mmol/230.0 mL = M K2SO4 7 7 7 8 8 8 8

8. Calculations Involving Molarity
Example 11-3: What volume of M NaOH solution would be required to completely neutralize 100 mL of M H3PO4? 8 8 8 9 9 9 9

9. Calculations for Acid-Base Titrations
Example 11-4: Calculate the molarity of a NaOH solution if 27.3 mL of it reacts with g of KHP. 12 12 13 13 13 13

10. Calculations for Acid-Base Titrations
Example 11-5: Calculate the molarity of a sulfuric acid solution if 23.2 mL of it reacts with g of Na2CO3. 14 14 15 15 15 15

11. Calculations for Acid-Base Titrations
Example 11-6: An impure sample of potassium hydrogen phthalate, KHP, had a mass of g. It was dissolved in water and titrated with 31.5 mL of M NaOH solution. Calculate the percent purity of the KHP sample.
NaOH + KHP → NaKP + H2O 16 16 17 17 17 17

12. Balancing Redox Reactions
Example 11-12: Tin (II) ions are oxidized to tin (IV) by bromine. Use the half reaction method to write and balance the net ionic equation. 40 39 41 41 41

13. Balancing Redox Reactions41 42 43 43 43

14. Balancing Redox Reactions42 43 44 44 44

15. Balancing Redox Reactions
Example 11-13: Dichromate ions oxidize iron (II) ions to iron (III) ions and are reduced to chromium (III) ions in acidic solution. Write and balance the net ionic equation for the reaction. 44 43 45 45 45

16. Balancing Redox Reactions44 45 47 47 46

17. Balancing Redox Reactions46 47 49 49 48

18. Balancing Redox Reactions48 49 51 51 50

19. Balancing Redox Reactions50 51 53 53 52

20. Calculations for Redox Titrations
Example 11-16: What volume of M KMnO4 is required to oxidize 35.0 mL of M HCl? The balanced reaction is: 52 51 54 54 53

21. Calculations for Redox Titrations
Example 11-17: A volume of 40.0 mL of iron (II) sulfate is oxidized to iron (III) by 20.0 mL of M potassium dichromate solution. What is the concentration of the iron (II) sulfate solution? 54 53 56 56 55

22. Synthesis Question