2. Entry Task: Feb 27 th -28 th Block #1 Grab New Entry task sheet Write the question down What are the mole ratios for this reaction? Be sure to label 2H 2 + O 2  2H 2 O You have 5 minutes!

3. Agenda: Sign off and Discuss Ch. 12.1 reading notes Stoichiometry notes#1

4. I can… Identify the quantitative relationship in a balanced chemical equation Determine the mole ratios from a balanced chemical reaction

6. Stoichiometry Stoichiometry is based on law of conservation of mass The law of conservation of mass states that the mass of reactants in a chemical reaction will equal the mass of products produced from that reaction.

7. Stoichiometry Write the reaction for iron reacting with oxygen 4Fe (s) + 3O 2 (g)  2Fe 2 O 3 (s) What do the coefficients represent? The represent the number of moles of that particular substance

8. Stoichiometry So in our Iron reacting with oxygen reaction, there are ____moles of iron reacting with ____moles of oxygen to produce ____ moles of Iron II oxide. 4 3 2

9. Stoichiometry We can change the number of moles (along with the molecular mass) to calculate this in to grams. 4Fe (s) + 3O 2 (g)  2Fe 2 O 3 (s) How many grams of iron are reacting in this equation? Convert from mole to gram.- Show work below. Fe= 55.85 g x 4 = 223.4 g 4 moles of Fe 1 moles of Fe 55.85 g of Fe = 223.4g of Fe

10. Stoichiometry 4Fe (s) + 3O 2 (g)  2Fe 2 O 3 (s) How many grams of oxygen are reacting in this equation? Convert from mole to gram.- Show work below. O= 15.99 g x 6 = 95.99 g 3 moles of O 2 1 moles of O 2 31.99 g of O 2 = 95.99 g of O 2

11. Stoichiometry 4Fe (s) + 3O 2 (g)  2Fe 2 O 3 (s) How many grams of iron II oxide are reacting in this equation? Convert from mole to gram.- Show work below. Fe 2 O 3 = (Fe x 4) 223.4 g 2 moles of Fe 2 O 3 1 moles of Fe 2 O 3 159.69 g of Fe 2 O 3 = 319.39 g of O 2 + (O x 6) 95.99 g = 319.39 g

12. Stoichiometry Mole Ratio: Is the ratio between the number of moles of any two substances in a balanced chemical equation Read through the Aluminum + bromine reaction- note the mole ratio relationships between reactants and between reactants and products.

13. Stoichiometry Practice Problems- Determine all possible the mole ratios for the following. 1. 4Al (s) + 3O 2 (g)  2Al 2 O 3 (s) What is the ratio between aluminum and oxygen? Answer: 4 mol of Al to 3 mol of O 2 OR 3 mol of O 2 to 4 mol of Al

14. Stoichiometry Practice Problems- Determine all possible the mole ratios for the following. 1. 4Al (s) + 3O 2 (g)  2Al 2 O 3 (s) What is the ratio between aluminum and aluminum oxide? Answer: 4 mol of Al to 2 mol of Al 2 O 3 OR 2 mol of Al 2 O 3 to 4 mol of Al

15. Stoichiometry Practice Problems- Determine all possible the mole ratios for the following. 1. 4Al (s) + 3O 2 (g)  2Al 2 O 3 (s) What is the ratio between oxygen and aluminum oxide? Answer: 3 mol of O 2 to 2 mol of Al 2 O 3 OR 2 mol of Al 2 O 3 to 3 mol of O 2

17. Chocolate Chip Cookies!! 1 cup butter 1/2 cup white sugar 1 cup packed brown sugar 1 teaspoon vanilla extract 2 eggs 2 1/2 cups all-purpose flour 1 teaspoon baking soda 1 teaspoon salt 2 cups semisweet chocolate chips Makes 3 dozen How many eggs are needed to make 3 dozen cookies? How much butter is needed for the amount of chocolate chips used? How many eggs would we need to make 9 dozen cookies? How much brown sugar would I need if I had 1 cup white sugar? 2 eggs 1 cup 6 eggs 2 cup

18. Cookies and Chemistry…Huh!?!? Just like chocolate chip cookies have recipes, chemists have recipes as well. Instead of calling them recipes, we call them reaction equations Furthermore, instead of using cups and teaspoons, we use moles. Lastly, instead of eggs, butter, sugar, etc. we use chemical compounds as ingredients.

19. Stoichiometry Stoichiometry is the study of quantitative relationships between amounts of reactants and products formed by a chemical reaction- RATIOS!!. ___H 2 (g) + ___O 2 (g)  ___H 2 O (l) 22 For this reaction, 2 moles of hydrogen gas reacts with 1 mole of oxygen gas to create 2 moles of water molecules.

20. Balance: ___H 2 (g) + ___O 2 (g)  ___H 2 O (l) 22 What is the ratio of hydrogen gas to oxygen gas?2 : 1 What is the ratio of oxygen gas to water?1 : 2 What is the ratio of hydrogen gas to water?2 : 2 What is the ratio of water to oxygen gas?2 : 1 Translate into written equation: 2 moles of hydrogen gas reacts with 1 mole of oxygen gas to produce 2 moles of water

21. 2H 2 (g) + O 2 (g)  2H 2 O(l) a. How many moles of H 2 were used if 4 moles of H 2 O were produced? = moles H 2 4 mol H 2 O 4 Mole ↔ mole Units match 2 mol H 2 O 2 mol H 2 b. How many moles of H 2 were used if 0.356 moles of H 2 O were produced? = moles H 2 0.356 molH 2 O 0.356 Units match 2 mol H 2 O 2 mol H 2 Mole ratio

22. 2H 2 (g) + O 2 (g)  2H 2 O(l) c. How many moles of O 2 were used if 2.36 moles of H 2 O were produced? = moles O 2 2.36 mol H 2 O 1.18 Mole ↔ mole Units match 2 mol H 2 O 1 mol O 2 d. How many moles of H 2 O were produced if 36.9 moles of H 2 were used? = moles H 2 O 36.9 mol H 2 36.9 Units match 2 mol H 2 2 mol H 2 O Mole ratio

23. You Try!! Silver metal reacts with sulfur solid (S 8 ) to create silver I sulfide. Provide a balanced equation below! 1. Formula of each substance, then set up equation, lastly balance the equation.

24. You Try!! Silver metal reacts with sulfur solid (S 8 ) to create silver I sulfide. Provide a balanced equation below! 1. Formula of each substance, then set up equation, lastly balance the equation. ___ Ag

25. You Try!! Silver metal reacts with sulfur solid (S 8 ) to create silver I sulfide. Provide a balanced equation below! 1. Formula of each substance, then set up equation, lastly balance the equation. ___Ag + ___S 8

26. You Try!! Silver metal reacts with sulfur solid (S 8 ) to create silver I sulfide. Provide a balanced equation below! 1. Formula of each substance, then set up equation, lastly balance the equation.  ___ Ag 2 S ___Ag + ___S 8

27. You Try!! Silver metal reacts with sulfur solid (S 8 ) to create silver I sulfide. Provide a balanced equation below! 1. Formula of each substance, then set up equation, lastly balance the equation.  ___ Ag 2 S ___Ag + ___S 8 816

28. a. How many moles of S 8 were used if 36 moles of Ag 2 S were produced? You Try!! Silver metal reacts with sulfur solid (S 8 ) to create silver I sulfide 16Ag + S 8  8Ag 2 S WHY did I balance the equation? To get the mole ratios

29. a. How many moles of S 8 were used if 36 moles of Ag 2 S were produced? You Try!! Silver metal reacts with sulfur solid (S 8 ) to create silver I sulfide Now What? Put starting amounts WITH label in correct spot 16Ag + S 8  8Ag 2 S 36 mol Ag 2 S

30. a. How many moles of S 8 were used if 36 moles of Ag 2 S were produced? You Try!! Silver metal reacts with sulfur solid (S 8 ) to create silver I sulfide 16Ag + S 8  8Ag 2 S What mole ratio would I use in this problem? 8 moles Ag 2 S 1 mole S 8 8 moles Ag 2 S

31. a. How many moles of S 8 were used if 36 moles of Ag 2 S were produced? You Try!! Silver metal reacts with sulfur solid (S 8 ) to create silver I sulfide WHY this ratio? 1 mole S 8 8 moles Ag 2 S 1 mole S 8 needs to be on top because that is what the question is asking for. 16Ag + S 8  8Ag 2 S

32. a. How many moles of S 8 were used if 36 moles of Ag 2 S were produced? You Try!! Silver metal reacts with sulfur solid (S 8 ) to create silver I sulfide 16Ag + S 8  8Ag 2 S 36 mol Ag 2 S 1 mole S 8 8 moles Ag 2 S

33. a. How many moles of S 8 were used if 36 moles of Ag 2 S were produced? = moles S 8 36 mol Ag 2 S 4.5 You Try!! Units match 8 mol Ag 2 S 1 mol S 8 Silver metal reacts with sulfur solid (S 8 ) to create silver I sulfide Mole ratio 16Ag + S 8  8Ag 2 S

34. You Try!! b. How many moles of Ag 2 S were produced if 7 moles of Ag were used? = moles Ag 2 S 7 mol Ag 3.5 Units match 16 mol Ag 8 mol Ag 2 S Silver metal reacts with sulfur solid (S 8 ) to create silver I sulfide Mole ratio 16Ag + S 8  8Ag 2 S

35. Stoichiometry- Grams ___H 2 (g) + ___O 2 (g)  ___H 2 O (l) 22 What is the molar mass of hydrogen gas? 4.028 g What is the molar mass of oxygen gas?31.998 g What is the molar mass of water?36.026 g

36. a. How many moles of H 2 were used if 72.0g of H 2 O were produced? = moles H 2 72.0 g H 2 O 4.00 gram ↔ mole 2H 2 (g) + O 2 (g)  2H 2 O(l) 72.0g? moles Units match 1 mol H 2 O 18 g H 2 O 2 mol H 2 O 2 mol H 2 72 X 2 = 144 18 X 2 = 36 Mole/Gram conversion Mole/Mole ratio

37. b. How many moles of H 2 O were produced if 36.5g of H 2 were used? = moles H 2 O 36.5 g H 2 18.1 gram ↔ mole 2H 2 (g) + O 2 (g)  2H 2 O(l) ? moles36.5 g Units match 1 mol H 2 2.014 g H 2 2 mol H 2 2 mol H 2 O 36.5 X 2 = 73 2.014 X 2 = 4.028 Mole/Gram conversion Mole/Mole ratio

38. You Try! Aluminum metal reacts with bromine gas to create aluminum bromide. Provide balanced equation below! 2Al + 3Br 2  2AlBr 3

39. a. How many moles of AlBr 3 were produced if 65.5g of Br 2 were used? = moles AlBr 3 65.5 g Br 2 0.273 You Try! 2Al + 3Br 2  2AlBr 3 ? moles65.5 g Units match 1 mol Br 2 159.808g Br 2 3 mol Br 2 2 mol AlBr 3 65.5 X 2 = 131 159.808 X 3 = 479.424 Mole/Gram conversion Mole/Mole ratio

40. b. How many moles of Al were used if 125g of AlBr 3 were produced? = moles Al 125 g AlBr 3 0.469 You Try! 2Al + 3Br 2  2AlBr 3 ? moles 125 g Units match 1 mol AlBr 3 266.69 g AlBr 3 2 mol AlBr 3 2 mol Al 125 X 2 = 250 266.69 X 2 = 533.38 Mole/Gram conversion Mole/Mole ratio

41. a. How many grams of AlBr 3 were produced if 2.35 moles of Al were used? = grams AlBr 3 2.35 moles Al 627 Moles  Grams 2Al + 3Br 2  2AlBr 3 ? grams 2.35 moles Units match 2 mol AlBr 3 2 mol Al1 mol AlBr 3 266.69 g AlBr 3 2.35 X 2 X 266.69 = 1253.443 2 Mole/Gram conversion Mole/Mole ratio

42. a. How many grams of Br 2 were used if 5.75 moles AlBr 3 were produced? = grams Br 2 5.75 moles AlBr 3 1378 Moles  Grams 2Al + 3Br 2  2AlBr 3 ? grams5.75 moles Units match 3 mol Br 2 2 mol AlBr 3 1 mol Br 2 159.808 g Br 2 5.75 X 3 X 159.808 = 2744.13 2 Mole/Gram conversion Mole/Mole ratio 1380

43. You Try! YOU TRY! Gold III sulfide reacts with hydrogen gas to create gold metal and dihydrogen monosulfide Provide balanced equation below! __Au 2 S 3 + __H 2  __Au + __ H 2 S

44. You Try! YOU TRY! Gold III sulfide reacts with hydrogen gas to create gold metal and dihydrogen monosulfide Provide balanced equation below! Au 2 S 3 + 3H 2  2Au + 3H 2 S

45. a. How many grams of H 2 S were produced 3.25 moles of hydrogen gas were used? = grams H 2 S 3.25 moles H 2 111 Moles  Grams Au 2 S 3 + 3H 2  2Au + 3H 2 S ? grams3.25 moles Units match 3 mol H 2 S 3 mol H 2 1 mol H 2 S 34.06 g H 2 S 3.25 X 3 X 34.06 = 332.085 3 Mole/Gram conversion Mole/Mole ratio

46. b. How many grams of H 2 were needed to react with 3.25 moles of gold III sulfide? = grams H 2 3.25 moles Au 2 S 3 19.6 Moles  Grams Au 2 S 3 + 3H 2  2Au + 3H 2 S ? grams3.25 moles Units match 3 mol H 2 1 mol Au 2 S 3 1 mol H 2 2.014 g H 2 3.25 X 3 X 2.014 = 19.6 1 Mole/Gram conversion Mole/Mole ratio