Difference between revisions of "Atom Economy"

Latest revision as of 17:39, 30 November 2019

Key Stage 4

Meaning

Atom Economy is the percentage of atoms in the reactants which ends up in the desired products.

About Atom Economy

During a chemical reaction there is often more than one product. When there is more than one product often one is desired and one is a waste product that must be disposed of.

To reduce costs and increase the efficiency of a process chemical engineers design systems that produce the maximum amount of a desired product and a minimum amount of waste products.

Atom Economy Equation

Percentage Atom Economy = [(Relative Formula Mass of Desired Product)/(Sum of Relative Formula Masses of Reactants)] x 100%

% Atom Economy = \(\frac{M_p}{M_r} \times 100%\)

Where:

M_p = Relative Formula Mass of Desired Product

M_r = Sum of Relative Formula Masses of Reactants

Example Calculations

Calculate the atom economy for producing Ammonia in the following reaction: N₂(g) + 3H₂(g) ⇌ 2NH₃(g)	Calculate the atom economy for producing Calcium Oxide in the following reaction: CaCO₃(s) → CaO(s) + CO₂(g)	Calculate the atom economy for producing Sodium Chloride in the following reaction: HCl(aq) + NaOH(aq) → NaCl(aq) + H₂O(l)
Find the Relative Formula Mass of the relevant reactants and product. M_r of N₂ = 28g M_r of H₂ = 2g M_r of NH₃ = 17g	Find the Relative Formula Mass of the relevant reactants and product. M_r of CaCO₃ = 100g M_r of CaO = 56g	Find the Relative Formula Mass of the relevant reactants and product. M_r of HCl = 36.5g M_r of NaOH = 40g M_r of NaCl = 58.5g
Find the total mass of reactants needed and the total mass of the desired product. Mass of Reactants = 28 + 3 x 2 Mass of Reactants = 34g Mass of desired Product = 2 x 17 Mass of desired Product = 34g	Find the total mass of reactants needed and the total mass of the desired product. Mass of Reactants = 100g Mass of desired Product = 56g	Find the total mass of reactants needed and the total mass of the desired product. Mass of Reactants = 36.5 + 40 Mass of Reactants = 76.5g Mass of desired Product = 58.5g
Substitute the values into the equation. % Atom Economy = \(\frac{M_p}{M_r} \times 100%\) % Atom Economy = \(\frac{34}{34} \times 100%\) % Atom Economy = 100%	Substitute the values into the equation. % Atom Economy = \(\frac{M_p}{M_r} \times 100%\) % Atom Economy = \(\frac{56}{100} \times 100%\) % Atom Economy = 56%	Substitute the values into the equation. % Atom Economy = \(\frac{M_p}{M_r} \times 100%\) % Atom Economy = \(\frac{58.5}{76.5} \times 100%\) % Atom Economy = 76.5%

References

@@ Line 4: / Line 4: @@
 ===About Atom Economy===
-: During a [[Chemical Reaction|chemical reaction]] there is often more than one [[product]]. When there is more than one [[product]] often one is desired and one is a [[Waste Product|waste product]] that must be [[disposal|disposed]] of.
+: During a [[Chemical Reaction|chemical reaction]] there is often more than one [[product]]. When there is more than one [[product]] often one is desired and one is a waste product that must be [[disposal|disposed]] of.
-: To reduce costs and increase the [[efficiency]] of a process [[Chemical Engineer|chemical engineers]] design systems that [[product|produce]] the maximum amount of a desired [[product]] and a minimum amount of [[Waste Products|waste products]].
+: To reduce costs and increase the efficiency of a process chemical engineers design systems that [[product|produce]] the maximum amount of a desired [[product]] and a minimum amount of waste products.
 ===Atom Economy Equation===
 Percentage Atom Economy = [(Relative Formula Mass of Desired Product)/(Sum of Relative Formula Masses of Reactants)] x 100%
-% Atom Economy = <math>frac{M_desiredproduct}{M_allreactants}</math>
+'' '''% Atom Economy''' '' = <math>\frac{M_p}{M_r} \times 100%</math>
 Where:
-M<sub>desiredproduct</sub> = Relative Formula Mass of Desired Product
+M<sub>p</sub> = Relative Formula Mass of Desired Product
-M<sub>allreactants</sub> = Sum of Relative Formula Masses of Reactants
+M<sub>r</sub> = Sum of Relative Formula Masses of Reactants
 ===Example Calculations===
@@ Line 81: / Line 81: @@
 | style="height:20px; width:300px; text-align:left;" |
-'''Find the number of [[mole]]s supplied of the known [[mass]].'''
+'''Substitute the values into the equation.'''
-No. [[Mole]]s = <math>\frac{Mass}{M_r}</math>
+'' '''% Atom Economy''' '' = <math>\frac{M_p}{M_r} \times 100%</math>
-No. [[Mole]]s = <math>\frac{48}{24}</math>
+'' '''% Atom Economy''' '' = <math>\frac{34}{34} \times 100%</math>
-No. [[Mole]]s = 2 mol
+'' '''% Atom Economy''' '' = 100%
-Therefore 2 [[mole]]s of MgO is produced.
-[[mole]]s of MgO = 40x2
-'''Yield''' = 80g
 | style="height:20px; width:300px; text-align:left;" |
-'''Find the number of [[mole]]s supplied of the known [[mass]].'''
+'''Substitute the values into the equation.'''
-No. [[Mole]]s = <math>\frac{Mass}{M_r}</math>
+'' '''% Atom Economy''' '' = <math>\frac{M_p}{M_r} \times 100%</math>
-No. [[Mole]]s = <math>\frac{320}{16}</math>
+'' '''% Atom Economy''' '' = <math>\frac{56}{100} \times 100%</math>
-No. [[Mole]]s = 20 mol
+'' '''% Atom Economy''' '' = 56%
-Therefore 40 [[mole]]s of H<sub>2</sub>O are produced.
-[[mole]]s of CO<sub>2</sub> = 18x40
-'''Yield''' = 720g
 | style="height:20px; width:300px; text-align:left;" |
-'''Find the number of [[mole]]s supplied of the known [[mass]].'''
+'''Substitute the values into the equation.'''
-No. [[Mole]]s = <math>\frac{Mass}{M_r}</math>
+'' '''% Atom Economy''' '' = <math>\frac{M_p}{M_r} \times 100%</math>
-No. [[Mole]]s = <math>\frac{7.3}{36.5}</math>
+'' '''% Atom Economy''' '' = <math>\frac{58.5}{76.5} \times 100%</math>
-No. [[Mole]]s = 0.2 mol
+'' '''% Atom Economy''' '' = 76.5%
+|}
-Therefore 0.2 [[mole]] of [[Sodium Chloride]] is produced.
-.2 [[mole]] of NaCl = 11.7g
+===References===
+====AQA====
+:[https://www.amazon.co.uk/gp/product/1471851346/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1471851346&linkCode=as2&tag=nrjc-21&linkId=3ac654f4b0da781c49c855a1af4c92ea ''Atom economy (atom utilisation), pages 79-80, GCSE Chemistry, Hodder, AQA '']
+:[https://www.amazon.co.uk/gp/product/1782945571/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782945571&linkCode=as2&tag=nrjc-21&linkId=9e29fad914244909903e5e93f8a01d47 ''Atom economy, page 48, GCSE Chemistry; The Revision Guide, CGP, AQA '']
+:[https://www.amazon.co.uk/gp/product/1782945962/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782945962&linkCode=as2&tag=nrjc-21&linkId=476bb5c8d1dfb5c08ac81b6d4d1c98d8 ''Atom economy, pages 138-140, GCSE Chemistry, CGP, AQA '']
+:[https://www.amazon.co.uk/gp/product/0198359381/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=0198359381&linkCode=as2&tag=nrjc-21&linkId=47c8d1ae58d8b3a5e2094cd447154558 ''Atom economy, pages 70-71, GCSE Chemistry; Third Edition, Oxford University Press, AQA '']
+:[https://www.amazon.co.uk/gp/product/0008158762/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=0008158762&linkCode=as2&tag=nrjc-21&linkId=a0fffa35b3ea49a63404f6704e0df7cc ''Atom; atom economy (atom utilisation), pages 97, 116-7, 323, 325, GCSE Chemistry; Student Book, Collins, AQA '']
+====Edexcel====
+:[https://www.amazon.co.uk/gp/product/1782945725/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782945725&linkCode=as2&tag=nrjc-21&linkId=694be7494de75af3349537d34e13f7f0 ''Atom economies, page 67, GCSE Chemistry; The Revision Guide, CGP, Edexcel '']
+:[https://www.amazon.co.uk/gp/product/1782948147/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782948147&linkCode=as2&tag=nrjc-21&linkId=f63dcd8345f4e49c717b39a228a36c7c ''Atom economies, pages 192-194, GCSE Chemistry, CGP, Edexcel  '']
+:[https://www.amazon.co.uk/gp/product/1292120215/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1292120215&linkCode=as2&tag=nrjc-21&linkId=8f96ddb76196848bafdb124354e4cf77 ''Atom economy, pages 110-111, GCSE Chemistry, Pearson, Edexcel '']
-'''Yield''' = 11.7g
+====OCR====
-|}
+:[https://www.amazon.co.uk/gp/product/0198359829/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=0198359829&linkCode=as2&tag=nrjc-21&linkId=90e8d7b4f039d53035238fa0320fe00b ''Atom economies, page 161, Gateway GCSE Chemistry, Oxford, OCR  '']
+:[https://www.amazon.co.uk/gp/product/1782945679/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782945679&linkCode=as2&tag=nrjc-21&linkId=a2db42f7b4bdf10cafaafa3bb9120940 ''Atom economy, page 67, GCSE Chemistry; The Revision Guide, CGP, OCR Gateway '']