1 / 26

Stoichiometry: Calculations and Conversions

This chapter covers the principles of stoichiometry, including ideal stoichiometric calculations, stoichiometric conversions, limiting reactant problems, and percent yield.

rebeccajoyce
Télécharger la présentation

Stoichiometry: Calculations and Conversions

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 9 Stoichiometry

  2. 9.1 & 9.2 Ideal Stoichiometric Calculations • Stoichiometry - the study of the quantitative measurement problems between chemical formulas, reactions and equations.

  3. Liters 22.4 L Mole Molar Mass 6.022 x1023 Atoms, molecules, particles Grams The Mole Map

  4. Stoichiometric Conversions • Quick Review using the mole map • Ex1: • 0.15 mol NaOH convert to grams • Ex2: • 9.00g MgCl2 convert to atoms of Chlorine

  5. Stoichiometric Conversions • Reaction stoichiometry • Example - combustion of propane: • C3H8 + __O2__CO2 + __H2O • Thus, for every 1 propane, 5 moles of diatomic oxygen are required to produce 3 moles of carbon dioxide and 4 moles of water.

  6. Liters Liters Coefficients Mole Mole Grams Molecules Grams The New Mole Map Molecules

  7. Stoichiometric Conversions • Four Core Steps: • Step #1 Write a BALANCED equation • Step #2 Go to moles • Step #3 Mole to Mole - cross the bridge • Step #4Go to the desired unit

  8. Stoichiometric Conversions • Ex1: How many moles of water vapor are created from 2 moles of Hydrogen? • Balanced equation • Go to Mole • Mole to Mole • Desired Unit

  9. Stoichiometric Conversions • Ex2: How many grams of water vapor are created from 64.0 grams of Oxygen? • Balanced equation • 2H2(g) + O2(g) 2H2O(g) • Go to Mole • Mole to Mole • Desired Unit

  10. Stoichiometric Conversions • Ex3: How many liters of H2O (g) are made from 5.00 L of Oxygen? • Balanced equation • 2H2(g) + O2(g) 2H2O(g) • Go to Mole • Mole to Mole • Desired Unit

  11. Stoichiometric Conversions • Ex4: How many Liters of Oxygen are needed to react with 14.40 g C5H12? • Balanced equation • Go to Mole • Mole to Mole • Desired Unit

  12. Stoichiometric Conversions • Ex5: How many grams of solid lithium hydroxide are needed to react with 8.50 grams of carbon dioxide gas? • (Lithium hydroxide + carbon dioxide yields Lithium carbonate and water) 9.23g LiOH

  13. Stoichiometric Conversions • Ex6: How many grams of water are produced from 2.00 moles of carbon dioxide and excess amount of lithium hydroxide? 36.0g • Ex7: How many moles of lithium carbonate are produced from 152 grams of carbon dioxide and an excess amount of lithium hydroxide? 3.45mol

  14. 9.3 Limiting Reactant Problems and % Yield... • The Limiting Reactant causes the reaction to stop…it is the reactant that is all used up in the chemical reaction.

  15. Limiting Reactant • Ex1: How many grams of Magnesium Chloride can be made from 3.64 g of magnesium and 7.10 g of Chlorine gas? • a: How much of the excess reactant did you use? • b: What percent of the excess was unused? ……

  16. Limiting Reactant • How many grams of Magnesium Chloride can be made from 3.64 g of magnesium and 7.10 g of Chlorine gas?

  17. Limiting Reactant • How much of the excess reactant did you use?

  18. Limiting Reactant • What percent of the excess was unused?

  19. Limiting Reactant and % Yield • .From the equation: 2 HCl + Zn  ZnCl2 + H2 • How many liters of H2 can be made starting with 20.0 grams of Zn and 25.5 g HCl? • How many grams of Zinc chloride will be made? • Identify the limiting and excess reactants. • How much of the excess reactant is needed? • How much of the excess reactant is left over?

  20. Limiting Reactant • 2 HCl + Zn  ZnCl2 + H2 • How many liters of H2 can be made starting with 20.0 grams of Zn and 25.5 g HCl?

  21. Limiting Reactant • 2 HCl + Zn  ZnCl2 + H2 • How many grams of Zinc chloride will be made?

  22. Limiting Reactant • 2 HCl + Zn  ZnCl2 + H2

  23. Limiting Reactant • Identify the limiting and excess reactants. • How much of the excess reactant is needed? • How much of the excess reactant is left over?

  24. % Yield • % yield = mass produced x 100 mass theoretically produced

  25. % Yield • Ex1: If combusting 9.62 g of SO2 produces 11.95 g of SO3, calculate the % yield.

  26. % Yield • Ex2: Reacting 4.20 grams of Nitrogen with 0.800 g of Hydrogen produces ?g of NH3 if there is a 75.5 % yield? Thus, the limiting reactant, H2, theoretically produces _________ grams of NH3. So, if the % yield is ________, then the actual yield is:

More Related