1 / 17

Stoichiometry

Stoichiometry. Chapter 9. Stoichiometry. The Proportional relationship between two or more substances during a chemical reaction. Definitions. Limiting Reactant – What gets used up in the chemical reaction Excess Reactant – Chemical that is used in a reaction but some is left over.

dinesh
Download Presentation

Stoichiometry

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. Stoichiometry Chapter 9

  2. Stoichiometry The Proportional relationship between two or more substances during a chemical reaction.

  3. Definitions Limiting Reactant – What gets used up in the chemical reaction Excess Reactant – Chemical that is used in a reaction but some is left over

  4. 4 Simple rules 1. Write Down the Given 2. Convert to moles 3. Use the mole ratio 4. Convert to desired units

  5. 4 Simple rules 1. Write Down the Given You need to know what you start with and what you need to end with.

  6. 4 Simple rules 2. Convert to moles One MOLE # of particle units Volume Mass Molar Mass from periodic table 22.4 L 6.02 x 1023atoms, molecules, or formula units

  7. 4 Simple rules 3. Use the mole ratio The mole ratio comes from the coefficients in a balanced Chemical Equation Where does the mole ratio come from?

  8. 4 Simple rules 3. Use the mole ratio Fe2O + 2 Li Li2O + 2 Fe What is the ratio between Fe and Fe2O?

  9. 4 Simple rules 3. Use the mole ratio Fe2O + 2 Li Li2O + 2 Fe What is the ratio between Fe and Li?

  10. 4 Simple rules 3. Use the mole ratio The coefficients can represent # of moles or # of molecules.

  11. 4 Simple rules 4. Convert to desired units If grams are desired use mass from P.T. If you need liters use 22.4L If you need atoms or molecules 6.02 x 1023 If moles are what is needed you are already done.

  12. Convert to desired unit. Grams from Periodic Table if mass 22.4 L if volume 6.02 x 1023 atoms/molecule Mole ratio of desired compound from the balanced equation. 1 mole of (starting element/ molecule) Write Down the given 1 mole of (ending element/ molecule) Mole ratio of given from balanced equation. Grams from Periodic Table if mass 22.4 L if volume 6.02 x 1023 atoms/molecules

  13. Example • If you have two givens it is a limiting reactant problem, solve both givens for their product. The smallest answer is the correct answer! • How many grams of Cu can be formed when 167.4 g of Fe reacts with 399.2 g of CuCl2? 2 Fe + 3 CuCl2 3 Cu + 2FeCl3

  14. 2 Fe + 3 CuCl2 3 Cu + 2FeCl3

  15. How many grams of excess are left over from problem #1? The math shows that you needed 110.4 g of Fe (2 moles Fe). Since you started with 167.4g Fe, all you need to do is subtract the two in order to find out how much excess you have. 167.4 g Fe (Given) -110.4 g Fe (Needed) 57.0 g Fe excess

  16. Finding % yield • Actual Yield x 100% = % yield Theoretical Yield • Actual Yield must be found experimentally. You must do the experiment yourself or they must give the information to you. You will see words like produced and formed in a problem that is giving you the actual yield. • Theoretical Yield is done using stoichiometry. You would take the given and find out how much of a product should be formed. It is a prediction and will always be done using math.

  17. The End

More Related