AN INTRODUCTION TO THE CHEMISTRY OF ALCOHOLS KNOCKHARDY PUBLISHING.
AN INTRODUCTION TO ATOM ECONOMY KNOCKHARDY PUBLISHING 2008 SPECIFICATIONS ©HOPTON.
-
Upload
elle-mawby -
Category
Documents
-
view
218 -
download
0
Transcript of AN INTRODUCTION TO ATOM ECONOMY KNOCKHARDY PUBLISHING 2008 SPECIFICATIONS ©HOPTON.
AN INTRODUCTION TOAN INTRODUCTION TO
ATOM ECONOMYATOM ECONOMY
KNOCKHARDY PUBLISHINGKNOCKHARDY PUBLISHING2008 2008
SPECIFICATIONSSPECIFICATIONS©HOPTON
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
KNOCKHARDY PUBLISHINGKNOCKHARDY PUBLISHING
ATOM ECONOMYATOM ECONOMY
©HOPTON
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.
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.
ATOM ECONOMYATOM 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
©HOPTON
ATOM ECONOMYATOM 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 ATOM ECONOMY
©HOPTON
MOLECULAR MASS OF DESIRED PRODUCT x 100
SUM OF MOLECULAR MASSES OF ALL PRODUCTS
MOLECULAR MASS OF DESIRED PRODUCT x 100
SUM OF MOLECULAR MASSES OF ALL PRODUCTS
WORKED CALCULATIONSWORKED CALCULATIONS
Calculate the atom economy for the formation of 1,2-dichloroethane, C2H4Cl2
©HOPTON
Example 1Example 1
WORKED CALCULATIONSWORKED CALCULATIONS
Calculate the atom economy for the formation of 1,2-dichloroethane, C2H4Cl2
Equation C2H4 + Cl2 ——> C2H4Cl2
Mr 28 71 99
©HOPTON
Example 1Example 1
WORKED CALCULATIONSWORKED CALCULATIONS
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
©HOPTON
Example 1Example 1
WORKED CALCULATIONSWORKED CALCULATIONS
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
©HOPTON
An ATOM ECONOMY of 100% is typical of an ADDITION REACTION
An ATOM ECONOMY of 100% is typical of an ADDITION REACTION
Example 1Example 1
WORKED CALCULATIONSWORKED CALCULATIONS
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
©HOPTON
An ATOM ECONOMY of 100% is typical of an ADDITION REACTION
An ATOM ECONOMY of 100% is typical of an ADDITION REACTION
Example 1Example 1
WORKED CALCULATIONSWORKED CALCULATIONS
Calculate the atom economy for the formation of nitrobenzene, C6H5NO2
©HOPTON
Example 2Example 2
WORKED CALCULATIONSWORKED CALCULATIONS
Calculate the atom economy for the formation of nitrobenzene, C6H5NO2
Equation C6H6 + HNO3 ——> C6H5NO2 + H2O
Mr 78 63 123 18
©HOPTON
An ATOM ECONOMY of 100% is not possible with a SUBSTITUTION REACTION
An ATOM ECONOMY of 100% is not possible with a SUBSTITUTION REACTION
Example 2Example 2
WORKED CALCULATIONSWORKED CALCULATIONS
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
©HOPTON
Example 2Example 2
WORKED CALCULATIONSWORKED CALCULATIONS
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
©HOPTON
Example 2Example 2
WORKED CALCULATIONSWORKED CALCULATIONS
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
©HOPTON
An ATOM ECONOMY of 100% is not possible with a SUBSTITUTION REACTION
An ATOM ECONOMY of 100% is not possible with a SUBSTITUTION REACTION
Example 2Example 2
WORKED CALCULATIONSWORKED CALCULATIONS
Calculate the atom economy for the preparation of ammonia from the thermal decomposition of ammonium sulphate.
©HOPTON
Example 3Example 3
WORKED CALCULATIONSWORKED CALCULATIONS
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
©HOPTON
Example 3Example 3
WORKED CALCULATIONSWORKED CALCULATIONS
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
©HOPTON
Example 3Example 3
WORKED CALCULATIONSWORKED CALCULATIONS
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)
©HOPTON
Example 3Example 3
WORKED CALCULATIONSWORKED CALCULATIONS
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)
©HOPTON
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.
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.
Example 3Example 3
CALCULATIONSCALCULATIONS
Calculate the atom economy of the following reactions (the required product is shown in red)
• CH3COCl + C2H5NH2 ——> CH3CONHC2H5 + HCl
• C2H5Cl + NaOH ——> C2H5OH + NaCl
• C2H5Cl + NaOH ——> C2H4 + H2O + NaCl
©HOPTON
CALCULATIONSCALCULATIONS
Calculate the atom economy of the following reactions (the required product is shown in red)
• CH3COCl + C2H5NH2 ——> CH3CONHC2H5 + HCl
• C2H5Cl + NaOH ——> C2H5OH + NaCl
• C2H5Cl + NaOH ——> C2H4 + H2O + NaCl
©HOPTON
70.2%70.2%
CALCULATIONSCALCULATIONS
Calculate the atom economy of the following reactions (the required product is shown in red)
• CH3COCl + C2H5NH2 ——> CH3CONHC2H5 + HCl
• C2H5Cl + NaOH ——> C2H5OH + NaCl
• C2H5Cl + NaOH ——> C2H4 + H2O + NaCl
©HOPTON
70.2%70.2%
55.8%55.8%
CALCULATIONSCALCULATIONS
Calculate the atom economy of the following reactions (the required product is shown in red)
• CH3COCl + C2H5NH2 ——> CH3CONHC2H5 + HCl
• C2H5Cl + NaOH ——> C2H5OH + NaCl
• C2H5Cl + NaOH ——> C2H4 + H2O + NaCl
©HOPTON
70.2%70.2%
55.8%55.8%
33.9%33.9%
OVERVIEWOVERVIEW
• 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
©HOPTON
OVERVIEWOVERVIEW
• 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
©HOPTON
OVERVIEWOVERVIEW
• 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
©HOPTON
OVERVIEWOVERVIEW
• 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
©HOPTON