1 / 56

CHAPTER 11

CHAPTER 11. Stoichiometry. 11.1 Analyzing a Chemical Reaction. Chemical equations tell stories…. 2CO(g) + O 2 (g) → 2CO 2 (g). Chemical equations tell stories…. 2CO(g) + O 2 (g) → 2CO 2 (g). … and stories can be put into different categories. Synthesis / Decomposition

dougal
Download Presentation

CHAPTER 11

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. CHAPTER 11 Stoichiometry 11.1 Analyzing a Chemical Reaction

  2. Chemical equations tell stories… 2CO(g) + O2(g) → 2CO2(g)

  3. Chemical equations tell stories… 2CO(g) + O2(g) → 2CO2(g) … and stories can be put into different categories Synthesis /Decomposition Single / Double replacement Precipitate reaction Polymerization reaction

  4. Chemical equations tell stories… But what exactly do they tell us? 2CO(g) + O2(g) 2CO2(g) They tell uswhat compounds we start with: Carbon monoxide (CO) gas Oxygen (O2) gas what compounds are formed: Carbon dioxide (CO2) gas

  5. 2CO(g) + O2(g) 2CO2(g) Chemical equations tell stories… What else do they tell us?

  6. 2CO(g) + O2(g) 2CO2(g) Chemical equations tell stories… What else do they tell us? 2CO molecules 1O2 molecules 2CO2 molecules They tell us how much of each compound is involved

  7. 2CO(g) + O2(g) 2CO2(g) Chemical equations tell stories… What else do they tell us? 2CO molecules 1O2 molecules 2CO2 molecules They tell us how much of each compound is involved stoichiometry: the study of the amounts of substances involved in a chemical reaction.

  8. 2CO(g) + O2(g) 2CO2(g) 2CO molecules 2 dozenCO molecules 2CO2 molecules 2 dozenCO2 molecules 1O2 molecules 1 dozenO2 molecules

  9. 2CO(g) + O2(g) 2CO2(g) 2CO molecules 2dozen CO molecules 2molesCO molecules 2CO2 molecules 2dozen CO2 molecules 2 molesCO2 molecules 1O2 molecules 1 dozenO2 molecules 1moleO2 molecules

  10. 2CO(g) + O2(g) 2CO2(g) 2 CO molecules 2 dozen CO molecules 2 moles CO molecules 2 x (6.023 x 1023)CO molecules 2CO2 molecules 2 dozen CO2 molecules 2 moles CO2 molecules 2 x (6.023 x 1023) CO2 molecules 1O2 molecules 1 dozen O2 molecules 1 mole O2 molecules (1 x) 6.023 x 1023 O2 molecules

  11. 2CO(g) + O2(g) 2CO2(g) Is that okay? Number of moles is notconserved + ≠ 2 moles CO molecules 1 mole O2 molecules 2 moles CO2 molecules

  12. 2CO(g) + O2(g) 2CO2(g) Is that okay? Yes, as long as the chemical equation is balanced! Number of moles is notconserved + ≠ 2 moles CO molecules 1 mole O2 molecules 2 moles CO2 molecules

  13. 2CO(g) + O2(g) 2CO2(g) 2 C atoms 2 O atoms 2 O atoms 2 C atoms 4 O atoms Number of atoms is conserved = + = This chemical equation isbalanced

  14. 2CO(g) + O2(g) 2CO2(g) Coefficients 2 moles CO molecules 1 mole O2 molecules 2 moles CO2 molecules This chemical equation isbalanced The coefficients are correct

  15. 2CO(g) + O2(g) 2CO2(g) These are important! Coefficients 2 moles CO molecules 1 mole O2 molecules 2 moles CO2 molecules This chemical equation isbalanced The coefficients are correct

  16. Coefficients are important 1 bag cake mix + 3 eggs + ¼ cup oil + 1 cup water 1 batch cupcakes

  17. Coefficients are important 1 bag cake mix + 3 eggs + ¼ cup oil + 1 cup water 1 batch cupcakes I need ¼ cup of oil to make 1 batch of cupcakes

  18. Coefficients are important 1 bag cake mix + 3 eggs + ¼ cup oil + 1 cup water 1 batch cupcakes Write as a ratio:

  19. Coefficients are important 1 bag cake mix + 3 eggs + ¼ cup oil + 1 cup water 1 batch cupcakes I need 1 cup of oil to make 4 batches of cupcakes

  20. Coefficients are important 1 bag cake mix + 3 eggs + ¼ cup oil + 1 cup water 1 batch cupcakes Write as a ratio:

  21. Coefficients are important Fermentation of sugar (glucose) into alcohol: C6H12O6(aq) 2C2H5OH(aq) + 2CO2(g) 1 mole glucose 2 moles ethanol 2 moles carbon dioxide

  22. Coefficients are important Fermentation of sugar (glucose) into alcohol: C6H12O6(aq) 2C2H5OH(aq) + 2CO2(g) 1 mole glucose 2 moles ethanol 2 moles carbon dioxide 1 moles 3 moles 2 moles 6 moles ethanol/ carbon dioxide x 3 glucose will yield

  23. Coefficients are important Fermentation of sugar (glucose) into alcohol: C6H12O6(aq) 2C2H5OH(aq) + 2CO2(g) 1 mole glucose 2 moles ethanol 2 moles carbon dioxide 1 moles 3 moles 7.5 moles 2 moles 6 moles 15 moles x 3 ethanol/ carbon dioxide x 7.5 glucose will yield

  24. Coefficients are important Fermentation of sugar (glucose) into alcohol: C6H12O6(aq) 2C2H5OH(aq) + 2CO2(g) 1 mole glucose 2 moles ethanol 2 moles carbon dioxide You MUST multiply all the coefficients by the same number 7.5C6H12O6(aq) 15C2H5OH(aq) + 15CO2(g) 7.5 moles glucose 15 moles ethanol 15 moles carbon dioxide

  25. Fermentation of sugar (glucose) into alcohol: C6H12O6(aq) 2C2H5OH(aq) + 2CO2(g) 1 mole glucose 2 moles ethanol 2 moles carbon dioxide Write as a ratio: These are stoichiometric equivalents

  26. Fermentation of sugar (glucose) into alcohol: C6H12O6(aq) 2C2H5OH(aq) + 2CO2(g) 1 mole glucose 2 moles ethanol 2 moles carbon dioxide Write as a ratio: mole ratio: a ratio comparison between substances in a balanced equation. It is obtained from the coefficients in the balanced equation.

  27. 11.1 Analyzing a Chemical Reaction Mole ratios Fermentation of sugar (glucose) into alcohol: C6H12O6(aq) 2C2H5OH(aq) + 2CO2(g) 1 mole glucose 2 moles ethanol 2 moles carbon dioxide mole ratios for this chemical equation

  28. Mole ratios Consider the following equation: CO(g) + 2H2(g) CH3OH(l) carbon monoxide hydrogen methanol Compare the reactant CO to the product CH3OH.

  29. Mole ratios Consider the following equation: CO(g) + 2H2(g) CH3OH(l) carbon monoxide hydrogen methanol Compare the reactant CO to the product CH3OH.

  30. Mole ratios Consider the following equation: CO(g) + 2H2(g) CH3OH(l) carbon monoxide hydrogen methanol If the reaction produces 5 moles of CH3OH, how many moles of H2 are consumed?

  31. Mole ratios Consider the following equation: CO(g) + 2H2(g) CH3OH(l) carbon monoxide hydrogen methanol If the reaction produces 5 moles of CH3OH, how many moles of H2 are consumed? Asked: moles of H2 Given: moles of CH3OH

  32. Mole ratios Consider the following equation: CO(g) + 2H2(g) CH3OH(l) carbon monoxide hydrogen methanol If the reaction produces 5 moles of CH3OH, how many moles of H2 are consumed? Write the mole ratio between H2 and CH3OH Write moles of H2 (asked) “on top” Asked: moles of H2 Given: moles of CH3OH

  33. Mole ratios Consider the following equation: CO(g) + 2H2(g) CH3OH(l) carbon monoxide hydrogen methanol If the reaction produces 5 moles of CH3OH, how many moles of H2 are consumed? Write the mole ratio between H2 and CH3OH Write moles of H2 (asked) “on top” Asked: moles of H2 “on top”

  34. Mole ratios Consider the following equation: CO(g) + 2H2(g) CH3OH(l) carbon monoxide hydrogen methanol If the reaction produces 5 moles of CH3OH, how many moles of H2 are consumed? Given: moles of CH3OH

  35. Mole ratios Consider the following equation: CO(g) + 2H2(g) CH3OH(l) carbon monoxide hydrogen methanol If the reaction produces 5 moles of CH3OH, how many moles of H2 are consumed? Asked: moles of H2

  36. A mixture of aluminum metal and chlorine gas reacts to form aluminum chloride (AlCl3): 2Al(s) + 3Cl2(g) → 2AlCl3(s). How many moles of aluminum chloride will form when 5 moles of chlorine gas react with excess aluminum metal?

  37. A mixture of aluminum metal and chlorine gas reacts to form aluminum chloride (AlCl3): 2Al(s) + 3Cl2(g) → 2AlCl3(s). How many moles of aluminum chloride will form when 5 moles of chlorine gas react with excess aluminum metal? Asked:moles AlCl3 Given:moles Cl2

  38. A mixture of aluminum metal and chlorine gas reacts to form aluminum chloride (AlCl3): 2Al(s) + 3Cl2(g) → 2AlCl3(s). How many moles of aluminum chloride will form when 5 moles of chlorine gas react with excess aluminum metal? Write the mole ratio between AlCl3 and Cl3 Write moles of AlCl3 (asked) “on top” Asked:moles AlCl3 Given:moles Cl2

  39. A mixture of aluminum metal and chlorine gas reacts to form aluminum chloride (AlCl3): 2Al(s) + 3Cl2(g) → 2AlCl3(s). How many moles of aluminum chloride will form when 5 moles of chlorine gas react with excess aluminum metal? Write the mole ratio between AlCl3 and Cl3 Write moles of AlCl3 (asked) “on top” Asked:moles AlCl3 Given:moles Cl2 “on top”

  40. A mixture of aluminum metal and chlorine gas reacts to form aluminum chloride (AlCl3): 2Al(s) + 3Cl2(g) → 2AlCl3(s). How many moles of aluminum chloride will form when 5 moles of chlorine gas react with excess aluminum metal? Asked:moles AlCl3 Given:moles Cl2

  41. A mixture of aluminum metal and chlorine gas reacts to form aluminum chloride (AlCl3): 2Al(s) + 3Cl2(g) → 2AlCl3(s). How many moles of aluminum chloride will form when 5 moles of chlorine gas react with excess aluminum metal? Asked:moles AlCl3 Given:moles Cl2 units cancel out

  42. A mixture of aluminum metal and chlorine gas reacts to form aluminum chloride (AlCl3): 2Al(s) + 3Cl2(g) → 2AlCl3(s). How many moles of aluminum chloride will form when 5 moles of chlorine gas react with excess aluminum metal? Asked:moles AlCl3 Given:moles Cl2 units cancel out

  43. A mixture of aluminum metal and chlorine gas reacts to form aluminum chloride (AlCl3): 2Al(s) + 3Cl2(g) → 2AlCl3(s). How many moles of aluminum chloride will form when 5 moles of chlorine gas react with excess aluminum metal? Asked:moles AlCl3 Given:moles Cl2 Answer:3.3 moles of AlCl3 are produced.

  44. There is no scale that measures in moles! How do you convert from moles to grams? The mass of 1 mole of Al is not the same as the mass of 1 mole of Cl2. How do you convert from grams of Al to grams of Cl2?

  45. There is no scale that measures in moles! How do you convert from moles to grams? By using the molar mass (g/mole) The mass of 1 mole of Al is not the same as the mass of 1 mole of Cl2. How do you convert from grams of Al to grams of Cl2? By using the molar mass (g/mole) and mole ratios

  46. Process for calculating grams from grams given

  47. If 45.0 g of calcium carbonate (CaCO3) decomposes in the reaction CaCO3(s) → CaO(s) + CO2(g), how many grams of CO2 are produced? Calcium carbonate (CaCO3) is present in rocks, eggshells and most seashells. CaCO3 decomposes when it is heated.

  48. If 45.0 g of calcium carbonate (CaCO3) decomposes in the reaction CaCO3(s) → CaO(s) + CO2(g), how many grams of CO2 are produced? Asked:grams of CO2 Given:grams of CaCO3 Relationships: mole ratios molar mass of CaCO3 = 40.078 + 12.011 + (15.999 x 3) = 100.0 g/mole molar mass of CO2 = 12.011 + (15.999 x 2) = 44.01 g/mole Strategy:

  49. If 45.0 g of calcium carbonate (CaCO3) decomposes in the reaction CaCO3(s) → CaO(s) + CO2(g), how many grams of CO2 are produced? Asked:grams of CO2 Given:grams of CaCO3 Relationships: mole ratios, molar mass of CaCO3 = 100.0 g/mole molar mass of CO2 = 44.01 g/mole 45.0 g CaCO3

  50. If 45.0 g of calcium carbonate (CaCO3) decomposes in the reaction CaCO3(s) → CaO(s) + CO2(g), how many grams of CO2 are produced? Asked: grams of CO2 Given: grams of CaCO3 Relationships: mole ratios, molar mass of CaCO3 = 100.0 g/mole molar mass of CO2 = 44.01 g/mole 45.0 g CaCO3 0.45 moles CaCO3

More Related