1 / 31

AN INTRODUCTION TO ATOM ECONOMY

© HOPTON. AN INTRODUCTION TO ATOM ECONOMY. 2008 SPECIFICATIONS. KNOCKHARDY PUBLISHING. © HOPTON. KNOCKHARDY PUBLISHING. ATOM ECONOMY. INTRODUCTION

christian
Télécharger la présentation

AN INTRODUCTION TO ATOM ECONOMY

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. ©HOPTON AN INTRODUCTION TO ATOM ECONOMY 2008 SPECIFICATIONS KNOCKHARDY PUBLISHING

  2. ©HOPTON KNOCKHARDY PUBLISHING ATOM ECONOMY INTRODUCTION This Powerpoint show is one of several produced to help students understand selected topics at AS and A2 level Chemistry. It is based on the requirements of the AQA and OCR specifications but is suitable for other examination boards. Individual students may use the material at home for revision purposes or it may be used for classroom teaching with an interactive white board. Accompanying notes on this, and the full range of AS and A2 topics, are available from the KNOCKHARDY SCIENCE WEBSITE at... www.knockhardy.org.uk/sci.htm All diagrams and animations in this Powerpoint are original and created by Jonathan Hopton. Permission must be obtained for their use in any commercial work.

  3. ©HOPTON ATOM ECONOMY

  4. ©HOPTON ATOM ECONOMY In most reactions you only want to make one of the resulting products Atom economy is a measure of how much of the products are useful A high atom economy means that there is less waste

  5. ©HOPTON ATOM ECONOMY In most reactions you only want to make one of the resulting products Atom economy is a measure of how much of the products are useful A high atom economy means that there is less waste ATOM ECONOMY MOLECULAR MASS OF DESIRED PRODUCT x 100 SUM OF MOLECULAR MASSES OF ALL PRODUCTS

  6. ©HOPTON WORKED CALCULATIONS

  7. ©HOPTON WORKED CALCULATIONS Example 1 Calculate the atom economy for the formation of 1,2-dichloroethane, C2H4Cl2

  8. ©HOPTON WORKED CALCULATIONS Example 1 Calculate the atom economy for the formation of 1,2-dichloroethane, C2H4Cl2 Equation C2H4 + Cl2 ——> C2H4Cl2 Mr 28 71 99

  9. ©HOPTON WORKED CALCULATIONS Example 1 Calculate the atom economy for the formation of 1,2-dichloroethane, C2H4Cl2 Equation C2H4 + Cl2 ——> C2H4Cl2 Mr 28 71 99 atom economy = molecular mass of C2H4Cl2 x 100 molecular mass of all products

  10. ©HOPTON WORKED CALCULATIONS Example 1 Calculate the atom economy for the formation of 1,2-dichloroethane, C2H4Cl2 Equation C2H4 + Cl2 ——> C2H4Cl2 Mr 28 71 99 atom economy = molecular mass of C2H4Cl2 x 100 molecular mass of all products = 99 x 100 = 100% 99 An ATOM ECONOMY of 100% is typical of an ADDITION REACTION

  11. ©HOPTON WORKED CALCULATIONS Example 1 Calculate the atom economy for the formation of 1,2-dichloroethane, C2H4Cl2 Equation C2H4 + Cl2 ——> C2H4Cl2 Mr 28 71 99 atom economy = molecular mass of C2H4Cl2 x 100 molecular mass of all products = 99 x 100 = 100% 99 An ATOM ECONOMY of 100% is typical of an ADDITION REACTION

  12. ©HOPTON WORKED CALCULATIONS Example 2 Calculate the atom economy for the formation of nitrobenzene, C6H5NO2

  13. ©HOPTON WORKED CALCULATIONS Example 2 Calculate the atom economy for the formation of nitrobenzene, C6H5NO2 Equation C6H6 + HNO3 ——> C6H5NO2 + H2O Mr 78 63 123 18 An ATOM ECONOMY of 100% is not possible with a SUBSTITUTION REACTION

  14. ©HOPTON WORKED CALCULATIONS Example 2 Calculate the atom economy for the formation of nitrobenzene, C6H5NO2 Equation C6H6 + HNO3 ——> C6H5NO2 + H2O Mr 78 63 123 18 atom economy = molecular mass of C6H5NO2 x 100 molecular mass of all products

  15. ©HOPTON WORKED CALCULATIONS Example 2 Calculate the atom economy for the formation of nitrobenzene, C6H5NO2 Equation C6H6 + HNO3 ——> C6H5NO2 + H2O Mr 78 63 123 18 atom economy = molecular mass of C6H5NO2 x 100 molecular mass of all products = 123 x 100 = 87.2% 123 + 18

  16. ©HOPTON WORKED CALCULATIONS Example 2 Calculate the atom economy for the formation of nitrobenzene, C6H5NO2 Equation C6H6 + HNO3 ——> C6H5NO2 + H2O Mr 78 63 123 18 atom economy = molecular mass of C6H5NO2 x 100 molecular mass of all products = 123 x 100 = 87.2% 123 + 18 An ATOM ECONOMY of 100% is not possible with a SUBSTITUTION REACTION

  17. ©HOPTON WORKED CALCULATIONS Example 3 Calculate the atom economy for the preparation of ammonia from the thermal decomposition of ammonium sulphate.

  18. ©HOPTON WORKED CALCULATIONS Example 3 Calculate the atom economy for the preparation of ammonia from the thermal decomposition of ammonium sulphate. Equation (NH4)2SO4 ——> H2SO4 + 2NH3 Mr 132 98 17

  19. ©HOPTON WORKED CALCULATIONS Example 3 Calculate the atom economy for the preparation of ammonia from the thermal decomposition of ammonium sulphate. Equation (NH4)2SO4 ——> H2SO4 + 2NH3 Mr 132 98 17 atom economy = 2 x molecular mass of NH3 x 100 molecular mass of all products

  20. ©HOPTON WORKED CALCULATIONS Example 3 Calculate the atom economy for the preparation of ammonia from the thermal decomposition of ammonium sulphate. Equation (NH4)2SO4 ——> H2SO4 + 2NH3 Mr 132 98 17 atom economy = 2 x molecular mass of NH3 x 100 molecular mass of all products = 2 x 17 = 25.8% 98 + (2 x 17)

  21. ©HOPTON WORKED CALCULATIONS Example 3 Calculate the atom economy for the preparation of ammonia from the thermal decomposition of ammonium sulphate. Equation (NH4)2SO4 ——> H2SO4 + 2NH3 Mr 132 98 17 atom economy = 2 x molecular mass of NH3 x 100 molecular mass of all products = 2 x 17 = 25.8% 98 + (2 x 17) In industry a low ATOM ECONOMY isn’t necessarily that bad if you can use some of the other products. If this reaction was used industrially, which it isn’t, the sulphuric acid would be a very useful by-product.

  22. ©HOPTON CALCULATIONS Calculate the atom economy of the following reactions (therequired product is shown in red) • CH3COCl + C2H5NH2 ——> CH3CONHC2H5 + HCl • C2H5Cl + NaOH ——> C2H5OH + NaCl • C2H5Cl + NaOH ——> C2H4 + H2O + NaCl

  23. ©HOPTON CALCULATIONS Calculate the atom economy of the following reactions (therequired product is shown in red) • CH3COCl + C2H5NH2 ——> CH3CONHC2H5 + HCl • C2H5Cl + NaOH ——> C2H5OH + NaCl • C2H5Cl + NaOH ——> C2H4 + H2O + NaCl 70.2%

  24. ©HOPTON CALCULATIONS Calculate the atom economy of the following reactions (therequired product is shown in red) • CH3COCl + C2H5NH2 ——> CH3CONHC2H5 + HCl • C2H5Cl + NaOH ——> C2H5OH + NaCl • C2H5Cl + NaOH ——> C2H4 + H2O + NaCl 70.2% 55.8%

  25. ©HOPTON CALCULATIONS Calculate the atom economy of the following reactions (therequired product is shown in red) • CH3COCl + C2H5NH2 ——> CH3CONHC2H5 + HCl • C2H5Cl + NaOH ——> C2H5OH + NaCl • C2H5Cl + NaOH ——> C2H4 + H2O + NaCl 70.2% 55.8% 33.9%

  26. ©HOPTON OVERVIEW

  27. ©HOPTON OVERVIEW • addition reactions will have 100% atom economy • substitution reactions will have less than 100% atom economy • elimination reactions will have less than 100% atom economy

  28. ©HOPTON OVERVIEW • addition reactions will have 100% atom economy • substitution reactions will have less than 100% atom economy • elimination reactions will have less than 100% atom economy • high atom economy = fewer waste materials = GREENER and MORE ECONOMICAL

  29. ©HOPTON OVERVIEW • addition reactions will have 100% atom economy • substitution reactions will have less than 100% atom economy • elimination reactions will have less than 100% atom economy • high atom economy = fewer waste materials = GREENER and MORE ECONOMICAL The percentage yield of a reaction must also be taken into consideration. • some reactions may have a high yield but a low atom economy • some reactions may have a high atom economy but a low yield

  30. ©HOPTON OVERVIEW • addition reactions will have 100% atom economy • substitution reactions will have less than 100% atom economy • elimination reactions will have less than 100% atom economy • high atom economy = fewer waste materials = GREENER and MORE ECONOMICAL The percentage yield of a reaction must also be taken into consideration. • some reactions may have a high yield but a low atom economy • some reactions may have a high atom economy but a low yield Reactions involving equilibria must also be considered

  31. ©HOPTON AN INTRODUCTION TO ATOM ECONOMY THE END ©2011 JONATHAN HOPTON & KNOCKHARDY PUBLISHING

More Related