1. Chemistry Notes Mole to Mole Calculations

2. Stoichiometry Stoichiometry means using balanced equations to calculate quantities of chemicals used in a chemical reaction

3. A chemical equation is like a recipe; it shows you how much of each “ingredient” is used and how much product you will have in the end.

4. N 2 + 3H 2  2NH 3

5. How many molecules of N 2 are there?

6. N 2 + 3H 2  2NH 3 How many molecules of N 2 are there? 1

7. N 2 + 3H 2  2NH 3 How many molecules of N 2 are there? 1 How many molecules of H 2 are there?

8. N 2 + 3H 2  2NH 3 How many molecules of N 2 are there? 1 How many molecules of H 2 are there? 3

9. N 2 + 3H 2  2NH 3 How many molecules of N 2 are there? 1 How many molecules of H 2 are there? 3 How many molecules of NH 3 are there?

10. N 2 + 3H 2  2NH 3 How many molecules of N 2 are there? 1 How many molecules of H 2 are there? 3 How many molecules of NH 3 are there? 2

11. N 2 + 3H 2  2NH 3 So one molecule of N 2 will react with 3 molecules of H 2 to form 2 molecules of NH 3.

12. N 2 + 3H 2  2NH 3 You could also say that one mole of N 2 will react with 3 moles of H 2 to form 2 moles of NH 3.

13. The heart of stoichiometry is using a balanced chemical equation as a conversion factor for dimensional analysis.

14. Zn + HCl  ZnCl 2 + H 2 For the above reaction, how many moles of zinc chloride can be produced with 0.27 moles of zinc?

15. Zn + HCl  ZnCl 2 + H 2 For the above reaction, how many moles of zinc chloride can be produced with 0.27 moles of zinc? Balance the equation first!!!

16. Zn + 2 HCl  ZnCl 2 + H 2 For the above reaction, how many moles of zinc chloride can be produced with 0.27 moles of zinc? Balance the equation first!!!

17. Zn + 2 HCl  ZnCl 2 + H 2 For the above reaction, how many moles of zinc chloride can be produced with 0.27 moles of zinc?

18. Zn + 2 HCl  ZnCl 2 + H 2 For the above reaction, how many moles of zinc will react with 1.39 moles of hydrochloric acid?

19. As an experiment... What is the ratio of the reaction of adding sodium to water, producing sodium hydroxide and hydrogen gas? Na + H 2 O  NaOH + H 2

20. As an experiment... What is the ratio of the reaction of adding sodium to water, producing sodium hydroxide and hydrogen gas? 2 Na + 2 H 2 O  2 NaOH + H 2

21. So if we started with 0.15 moles of sodium metal, how many moles of hydrogen gas was produced?

22. Why are mole/mole problems impractical in a laboratory setting?

23. We don’t measure directly in moles!

24. Why are mole/mole problems impractical in a laboratory setting? We don’t measure directly in moles! Balances measure in grams.