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Difference between revisions of "Concentration"
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===Meaning===
 
===Meaning===
 
[[Concentration]] is the [[ratio]] of a [[solute]] to a [[solvent]].
 
[[Concentration]] is the [[ratio]] of a [[solute]] to a [[solvent]].
 +
 +
or
 +
 +
The relative abundance of [[particle]]s in a region.
  
 
===About Concentration===
 
===About Concentration===
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===About Concentration===
 
===About Concentration===
 
: [[Concentration]] can be measured in g/dm<sup>3</sup> or mol/dm<sup>3</sup> ([[Molarity]]).
 
: [[Concentration]] can be measured in g/dm<sup>3</sup> or mol/dm<sup>3</sup> ([[Molarity]]).
−
: When calculating [[concentration]] in g/dm<sup>3</sup> the [[mass]] of the [[solute]] is [[measure]]d in [[gram]]s and the [[Volume (Space)|volume]] of [[solvent]] is [[measure]]d in [[decimetres cubed]].
+
: When calculating [[concentration]] in g/dm<sup>3</sup> the [[mass]] of the [[solute]] is [[measure]]d in [[gram]]s and the [[Volume (Space)|volume]] of [[solvent]] is [[measure]]d in [[Decimetres Cubed|decimetres cubed]].
−
: When calculating [[concentration]] in mol/dm<sup>3</sup> the amount of [[solute]] is [[measure]]d in [[Mole]]s by finding the [[mass]] and the [[Relative Formula Mass|relative formula mass]] of the [[chemical]] to find out the number of [[mole]]s and the [[Volume (Space)|volume]] of [[solvent]] is [[measure]]d in [[decimetres cubed]].
+
: When calculating [[concentration]] in mol/dm<sup>3</sup> the amount of [[solute]] is [[measure]]d in [[Mole]]s by finding the [[mass]] and the [[Relative Formula Mass|relative formula mass]] of the [[chemical]] to find out the number of [[mole]]s and the [[Volume (Space)|volume]] of [[solvent]] is [[measure]]d in [[Decimetres Cubed|decimetres cubed]].
  
 
===Equation===
 
===Equation===
 
====Concentration by Mass====
 
====Concentration by Mass====
−
concentration (g/dm<sup>3</sup>) = <math>\frac{mass (g)}{volume (dm^3)}</math>
+
'' '''concentration (g/dm<sup>3</sup>)''' '' = <math>\frac{mass (g)}{volume (dm^3)}</math>
  
 
Where:
 
Where:
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====Concentration by Moles====
 
====Concentration by Moles====
−
concentration (g/dm<sup>3</sup>) = <math>\frac{Moles (mol)}{volume (dm^3)}</math>
+
'' '''concentration (mol/dm<sup>3</sup>)''' '' = <math>\frac{Moles (mol)}{volume (dm^3)}</math>
  
 
Where:
 
Where:
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: volume = The [[Volume (Space)|volume]] of [[solvent]].
 
: volume = The [[Volume (Space)|volume]] of [[solvent]].
  
 +
===Calculating Concentration===
 +
====Concentration by Mass====
 +
{| class="wikitable"
 +
|-
 +
| style="height:20px; width:300px; text-align:center;" |117g of [[NaCl]] is [[dissolve]]d in 0.5dm<sup>3</sup> of [[water]]. Calculate the [[concentration]] in g/dm<sup>3</sup>.
 +
| style="height:20px; width:300px; text-align:center;" |28g of [[KOH]] is [[dissolve]]d in 100ml of [[water]]. Calculate the [[concentration]] in g/dm<sup>3</sup>.
 +
| style="height:20px; width:300px; text-align:center;" |73g of [[HCl]] is [[dissolve]]d in 400ml of [[water]]. Calculate the [[concentration]] in g/dm<sup>3</sup>.
 +
|-
 +
| style="height:20px; width:200px; text-align:left;" |
 +
'''State the [[mass]] in [[gram]]s and the [[Volume (Space)|volume]] in dm<sup>3</sup>:'''
 +
 +
[[mass]] = 117g
 +
 +
[[Volume (Space)|volume]] = 0.5dm<sup>3</sup>
 +
| style="height:20px; width:200px; text-align:left;" |
 +
'''State the [[mass]] in [[gram]]s and the [[Volume (Space)|volume]] in dm<sup>3</sup>:'''
 +
 +
[[mass]] = 28g
 +
 +
[[Volume (Space)|volume]] = 100ml
 +
 +
The [[Volume (Space)|volume]] must be converted into dm<sup>3</sup> from ml.
 +
 +
[[Volume (Space)|volume]] in dm<sup>3</sup> = ([[Volume (Space)|volume]] in ml)/1000
 +
 +
[[Volume (Space)|volume]] = 0.1dm<sup>3</sup>
 +
| style="height:20px; width:200px; text-align:left;" |
 +
'''State the [[mass]] in [[gram]]s and the [[Volume (Space)|volume]] in dm<sup>3</sup>:'''
 +
 +
[[mass]] = 73g
 +
 +
[[Volume (Space)|volume]] = 400ml
 +
 +
The [[Volume (Space)|volume]] must be converted into dm<sup>3</sup> from ml.
 +
 +
[[Volume (Space)|volume]] in dm<sup>3</sup> = ([[Volume (Space)|volume]] in ml)/1000
 +
 +
[[Volume (Space)|volume]] = 0.4dm<sup>3</sup>
 +
|-
 +
| style="height:20px; width:300px; text-align:left;" |
 +
'''Calculate the Concentration:'''
 +
 +
'' '''concentration (g/dm<sup>3</sup>)''' '' = <math>\frac{mass (g)}{volume (dm^3)}</math>
 +
 +
'' '''concentration''' '' = <math>\frac{117}{0.5}</math>
 +
 +
'' '''concentration''' '' = 234g/dm<sup>3</sup>
 +
| style="height:20px; width:300px; text-align:left;" |
 +
'''Calculate the Concentration:'''
 +
 +
'' '''concentration (g/dm<sup>3</sup>)''' '' = <math>\frac{mass (g)}{volume (dm^3)}</math>
 +
 +
'' '''concentration''' '' = <math>\frac{28}{0.1}</math>
 +
 +
'' '''concentration''' '' = 280g/dm<sup>3</sup>
 +
| style="height:20px; width:300px; text-align:left;" |
 +
'''Calculate the Concentration:'''
 +
 +
'' '''concentration (g/dm<sup>3</sup>)''' '' = <math>\frac{mass (g)}{volume (dm^3)}</math>
 +
 +
'' '''concentration''' '' = <math>\frac{73}{0.4}</math>
 +
 +
'' '''concentration''' '' = 182.5g/dm<sup>3</sup>
 +
|}
 +
 +
====Concentration as Molarity====
 +
{| class="wikitable"
 +
|-
 +
| style="height:20px; width:300px; text-align:center;" |117g of [[NaCl]] is [[dissolve]]d in 0.5dm<sup>3</sup> of [[water]]. Calculate the [[concentration]] in g/dm<sup>3</sup>.
 +
| style="height:20px; width:300px; text-align:center;" |28g of [[KOH]] is [[dissolve]]d in 100ml of [[water]]. Calculate the [[concentration]] in g/dm<sup>3</sup>.
 +
| style="height:20px; width:300px; text-align:center;" |7.3g of [[HCl]] is [[dissolve]]d in 400ml of [[water]]. Calculate the [[concentration]] in g/dm<sup>3</sup>.
 +
|-
 +
| style="height:20px; width:200px; text-align:left;" |
 +
'''Find the number of [[mole]]s.'''
 +
[[mass]] = 117g
 +
 +
[[Relative Formula Mass]] = 58.5g
 +
 +
Number of [[Mole]]s of a [[Compound]] = ([[Mass]] of [[compound]])/([[Relative Formula Mass]] of [[compound]])
 +
 +
Number of [[Mole]]s = <math>{\frac{m}{M_r}}</math>
 +
 +
Number of [[Mole]]s = <math>{\frac{117}{58.5}}</math>
 +
 +
Number of [[Mole]]s = 2mol
 +
 +
 +
| style="height:20px; width:200px; text-align:left;" |
 +
'''State the [[mass]] in [[gram]]s and the [[Volume (Space)|volume]] in dm<sup>3</sup>:'''
 +
'''Find the number of [[mole]]s.'''
 +
[[mass]] = 28g
 +
 +
[[Relative Formula Mass]] = 56g
 +
 +
Number of [[Mole]]s of a [[Compound]] = ([[Mass]] of [[compound]])/([[Relative Formula Mass]] of [[compound]])
 +
 +
Number of [[Mole]]s = <math>{\frac{m}{M_r}}</math>
 +
 +
Number of [[Mole]]s = <math>{\frac{28}{56}}</math>
 +
 +
Number of [[Mole]]s = 0.5mol
 +
| style="height:20px; width:200px; text-align:left;" |
 +
'''Find the number of [[mole]]s.'''
 +
[[mass]] = 7.3g
 +
 +
[[Relative Formula Mass]] = 36.5g
 +
 +
Number of [[Mole]]s of a [[Compound]] = ([[Mass]] of [[compound]])/([[Relative Formula Mass]] of [[compound]])
 +
 +
Number of [[Mole]]s = <math>{\frac{m}{M_r}}</math>
 +
 +
Number of [[Mole]]s = <math>{\frac{7.3}{36.5}}</math>
 +
 +
Number of [[Mole]]s = 0.2mol
 +
|-
 +
| style="height:20px; width:300px; text-align:left;" |
 +
[[Volume (Space)|volume]] = 0.5dm<sup>3</sup>
 +
| style="height:20px; width:300px; text-align:left;" |
 +
[[Volume (Space)|volume]] = 100ml
 +
 +
The [[Volume (Space)|volume]] must be converted into dm<sup>3</sup> from ml.
 +
 +
[[Volume (Space)|volume]] in dm<sup>3</sup> = ([[Volume (Space)|volume]] in ml)/1000
 +
 +
[[Volume (Space)|volume]] = 0.1dm<sup>3</sup>
 +
| style="height:20px; width:300px; text-align:left;" |
 +
[[Volume (Space)|volume]] = 400ml
 +
 +
The [[Volume (Space)|volume]] must be converted into dm<sup>3</sup> from ml.
 +
 +
[[Volume (Space)|volume]] in dm<sup>3</sup> = ([[Volume (Space)|volume]] in ml)/1000
 +
 +
[[Volume (Space)|volume]] = 0.4dm<sup>3</sup>
 +
 +
|-
 +
| style="height:20px; width:300px; text-align:left;" |
 +
'''Calculate the Concentration:'''
 +
 +
'' '''concentration (mol/dm<sup>3</sup>)''' '' = <math>\frac{Moles (mol)}{volume (dm^3)}</math>
 +
 +
'' '''concentration''' '' = <math>\frac{2}{0.5}</math>
 +
 +
'' '''concentration''' '' = 4mol/dm<sup>3</sup> = 4M
 +
| style="height:20px; width:300px; text-align:left;" |
 +
'''Calculate the Concentration:'''
 +
 +
'' '''concentration (mol/dm<sup>3</sup>)''' '' = <math>\frac{Moles (mol)}{volume (dm^3)}</math>
 +
 +
'' '''concentration''' '' = <math>\frac{0.5}{0.1}</math>
 +
 +
'' '''concentration''' '' = 5mol/dm<sup>3</sup> = 5M
 +
| style="height:20px; width:300px; text-align:left;" |
 +
'''Calculate the Concentration:'''
 +
 +
'' '''concentration (mol/dm<sup>3</sup>)''' '' = <math>\frac{mass (g)}{volume (dm^3)}</math>
 +
 +
'' '''concentration''' '' = <math>\frac{0.2}{0.4}</math>
 +
 +
'' '''concentration''' '' = 0.5mol/dm<sup>3</sup> = 5M
 +
|}
 +
 +
===References===
 +
====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 ''Concentration, page 193, GCSE Chemistry; Student Book, Collins, 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 ''Concentration, pages 72-77, 134-135, 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 ''Concentration; and equilibrium, page 214-5, GCSE Chemistry; Student Book, Collins, 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 ''Concentration; and reaction rate, pages 200-1, 204, 206-7, GCSE Chemistry; Student Book, Collins, AQA '']
 +
:[https://www.amazon.co.uk/gp/product/1471851362/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1471851362&linkCode=as2&tag=nrjc-21&linkId=7d78d70a2044ee9982dae010c94af92a ''Concentration; Effect on dynamic equilibrium, pages 132, GCSE Combined Science Trilogy 2, Hodder, AQA  '']
 +
:[https://www.amazon.co.uk/gp/product/1471851362/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1471851362&linkCode=as2&tag=nrjc-21&linkId=7d78d70a2044ee9982dae010c94af92a ''Concentration; Effect on the rate of a reaction, pages 123, 125, 127, 129, GCSE Combined Science Trilogy 2, Hodder, 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 ''Concentration; of acid, page 153, GCSE Chemistry; Student Book, Collins, 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 ''Concentration; of solution, pages 112-3, 118-9, 125, GCSE Chemistry; Student Book, Collins, 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 ''Concentration; titrations, pages 88-90, GCSE Chemistry, Hodder, AQA '']
 +
:[https://www.amazon.co.uk/gp/product/1471851354/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1471851354&linkCode=as2&tag=nrjc-21&linkId=9012a0d354024419214fb3ad5ac44ba0 ''Concentrations of solutions, page 193, GCSE Combined Science Trilogy 1, Hodder, AQA '']
 +
:[https://www.amazon.co.uk/gp/product/1782945598/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782945598&linkCode=as2&tag=nrjc-21&linkId=ad276ad49df77ab4b40ab4fd0fe09796 ''Concentrations, page 126, GCSE Combined Science; The Revision Guide, CGP, AQA '']
 +
:[https://www.amazon.co.uk/gp/product/178294639X/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=178294639X&linkCode=as2&tag=nrjc-21&linkId=51599bb45a2bfaf7c1b6a978b2ca2616 ''Concentrations, pages 118-120, GCSE Combined Science Trilogy; Chemistry, 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 ''Concentrations, pages 129-135, GCSE Chemistry, CGP, 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=9e29fad914244909903e5e93f8a01d87 ''Concentrations, pages 46, 47, GCSE Chemistry; The Revision Guide, CGP, AQA '']
 +
 +
====Edexcel====
 +
 +
:[https://www.amazon.co.uk/gp/product/1292120193/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1292120193&linkCode=as2&tag=nrjc-21&linkId=572df39392fb4200db8391d98ae6314e ''Concentration, pages 20, 88, 197, GCSE Combined Science, Pearson Edexcel '']
 +
:[https://www.amazon.co.uk/gp/product/1292120207/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1292120207&linkCode=as2&tag=nrjc-21&linkId=22455ff53961978667722edaa64c0be5 ''Concentration, pages 24, 126, 164, GCSE Biology, Pearson, 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 ''Concentration, pages 29, 44, 65, GCSE Chemistry; The Revision Guide, 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 ''Concentration, pages 53, 112-113, GCSE Chemistry, Pearson, 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 ''Concentration, pages 80, 81, 123, 124, 187, 188, GCSE Chemistry, CGP, Edexcel  '']
 +
:[https://www.amazon.co.uk/gp/product/1782945741/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782945741&linkCode=as2&tag=nrjc-21&linkId=30da4f2178da182547b62a7329d13b57 ''Concentration, pages 92, 106, GCSE Combined Science; The Revision Guide, CGP, Edexcel '']
 +
:[https://www.amazon.co.uk/gp/product/1782945741/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782945741&linkCode=as2&tag=nrjc-21&linkId=30da4f2178da182547b62a7329d13b57 ''Concentration; effect on equilibrium, page 122, GCSE Combined Science; The Revision Guide, CGP, 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 ''Concentration; effect on equilibrium, page 60, 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 ''Concentration; effect on equilibrium, pages 173, 203, GCSE Chemistry, CGP, Edexcel  '']
 +
:[https://www.amazon.co.uk/gp/product/1782945741/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782945741&linkCode=as2&tag=nrjc-21&linkId=30da4f2178da182547b62a7329d13b57 ''Concentration; effect on rate, pages 129, 132, GCSE Combined Science; 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 ''Concentration; effect on rate, pages 232, 235, 236, GCSE Chemistry, CGP, 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 ''Concentration; effect on rate, pages 78, 81, GCSE Chemistry; The Revision Guide, CGP, Edexcel '']
  
−
===Calculating Concentration===
+
====OCR====
 +
:[https://www.amazon.co.uk/gp/product/1782945695/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782945695&linkCode=as2&tag=nrjc-21&linkId=ceafcc80bcad6b6754ee97a0c7ceea53 ''Concentration (effect on reaction rate), page 131, Gateway GCSE Combined Science; The Revision Guide, CGP, 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 ''Concentration, pages 44, 63, 64, GCSE Chemistry; The Revision Guide, CGP, OCR Gateway '']
 +
:[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 ''Concentration; acids, pages 118-119, 274-275, Gateway GCSE Chemistry, Oxford, 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 ''Concentration; calculations, pages 164-165, 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 ''Concentration; effect on equilibrium, page 74, GCSE Chemistry; The Revision Guide, CGP, OCR Gateway '']
 +
:[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 ''Concentration; effect on rate, page 71, GCSE Chemistry; The Revision Guide, CGP, OCR Gateway '']
 +
:[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 ''Concentration; equilibrium position, page 188-189, 190, Gateway GCSE Chemistry, Oxford, 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 ''Concentration; reaction rates, pages 178-179, Gateway GCSE Chemistry, Oxford, OCR  '']

Latest revision as of 12:06, 23 February 2022

Key Stage 2

Meaning

Concentration is how dilute or concentrated a solution is.

About Concentration

When orange juice is added to water if there is a lot of water but not much orange juice then the solution is dilute. If there is a lot of orange juice, but very little water then it is concentrated.

Key Stage 3

Meaning

Concentration is the ratio of a solute to a solvent.

or

The relative abundance of particles in a region.

About Concentration

The more solute in a solution the higher the concentration.
The more solvent in a solution the lower the concentration.
Concentration can have several units but the most common one used in science is Molarity (M).

Key Stage 4

Meaning

Concentration is the ratio of the mass of solute to the volume of solvent.

About Concentration

Concentration can be measured in g/dm3 or mol/dm3 (Molarity).
When calculating concentration in g/dm3 the mass of the solute is measured in grams and the volume of solvent is measured in decimetres cubed.
When calculating concentration in mol/dm3 the amount of solute is measured in Moles by finding the mass and the relative formula mass of the chemical to find out the number of moles and the volume of solvent is measured in decimetres cubed.

Equation

Concentration by Mass

concentration (g/dm3) = \(\frac{mass (g)}{volume (dm^3)}\)

Where:

mass = The mass of the solute.
volume = The volume of solvent.

Concentration by Moles

concentration (mol/dm3) = \(\frac{Moles (mol)}{volume (dm^3)}\)

Where:

Moles = The number of moles of the solute. Found by dividing the mass in grams by the relative formula mass.
volume = The volume of solvent.

Calculating Concentration

Concentration by Mass

117g of NaCl is dissolved in 0.5dm3 of water. Calculate the concentration in g/dm3. 28g of KOH is dissolved in 100ml of water. Calculate the concentration in g/dm3. 73g of HCl is dissolved in 400ml of water. Calculate the concentration in g/dm3.

State the mass in grams and the volume in dm3:

mass = 117g

volume = 0.5dm3

State the mass in grams and the volume in dm3:

mass = 28g

volume = 100ml

The volume must be converted into dm3 from ml.

volume in dm3 = (volume in ml)/1000

volume = 0.1dm3

State the mass in grams and the volume in dm3:

mass = 73g

volume = 400ml

The volume must be converted into dm3 from ml.

volume in dm3 = (volume in ml)/1000

volume = 0.4dm3

Calculate the Concentration:

concentration (g/dm3) = \(\frac{mass (g)}{volume (dm^3)}\)

concentration = \(\frac{117}{0.5}\)

concentration = 234g/dm3

Calculate the Concentration:

concentration (g/dm3) = \(\frac{mass (g)}{volume (dm^3)}\)

concentration = \(\frac{28}{0.1}\)

concentration = 280g/dm3

Calculate the Concentration:

concentration (g/dm3) = \(\frac{mass (g)}{volume (dm^3)}\)

concentration = \(\frac{73}{0.4}\)

concentration = 182.5g/dm3

Concentration as Molarity

117g of NaCl is dissolved in 0.5dm3 of water. Calculate the concentration in g/dm3. 28g of KOH is dissolved in 100ml of water. Calculate the concentration in g/dm3. 7.3g of HCl is dissolved in 400ml of water. Calculate the concentration in g/dm3.

Find the number of moles. mass = 117g

Relative Formula Mass = 58.5g

Number of Moles of a Compound = (Mass of compound)/(Relative Formula Mass of compound)

Number of Moles = \({\frac{m}{M_r}}\)

Number of Moles = \({\frac{117}{58.5}}\)

Number of Moles = 2mol


State the mass in grams and the volume in dm3: Find the number of moles. mass = 28g

Relative Formula Mass = 56g

Number of Moles of a Compound = (Mass of compound)/(Relative Formula Mass of compound)

Number of Moles = \({\frac{m}{M_r}}\)

Number of Moles = \({\frac{28}{56}}\)

Number of Moles = 0.5mol

Find the number of moles. mass = 7.3g

Relative Formula Mass = 36.5g

Number of Moles of a Compound = (Mass of compound)/(Relative Formula Mass of compound)

Number of Moles = \({\frac{m}{M_r}}\)

Number of Moles = \({\frac{7.3}{36.5}}\)

Number of Moles = 0.2mol

volume = 0.5dm3

volume = 100ml

The volume must be converted into dm3 from ml.

volume in dm3 = (volume in ml)/1000

volume = 0.1dm3

volume = 400ml

The volume must be converted into dm3 from ml.

volume in dm3 = (volume in ml)/1000

volume = 0.4dm3

Calculate the Concentration:

concentration (mol/dm3) = \(\frac{Moles (mol)}{volume (dm^3)}\)

concentration = \(\frac{2}{0.5}\)

concentration = 4mol/dm3 = 4M

Calculate the Concentration:

concentration (mol/dm3) = \(\frac{Moles (mol)}{volume (dm^3)}\)

concentration = \(\frac{0.5}{0.1}\)

concentration = 5mol/dm3 = 5M

Calculate the Concentration:

concentration (mol/dm3) = \(\frac{mass (g)}{volume (dm^3)}\)

concentration = \(\frac{0.2}{0.4}\)

concentration = 0.5mol/dm3 = 5M

References

AQA

Concentration, page 193, GCSE Chemistry; Student Book, Collins, AQA
Concentration, pages 72-77, 134-135, GCSE Chemistry; Third Edition, Oxford University Press, AQA
Concentration; and equilibrium, page 214-5, GCSE Chemistry; Student Book, Collins, AQA
Concentration; and reaction rate, pages 200-1, 204, 206-7, GCSE Chemistry; Student Book, Collins, AQA
Concentration; Effect on dynamic equilibrium, pages 132, GCSE Combined Science Trilogy 2, Hodder, AQA
Concentration; Effect on the rate of a reaction, pages 123, 125, 127, 129, GCSE Combined Science Trilogy 2, Hodder, AQA
Concentration; of acid, page 153, GCSE Chemistry; Student Book, Collins, AQA
Concentration; of solution, pages 112-3, 118-9, 125, GCSE Chemistry; Student Book, Collins, AQA
Concentration; titrations, pages 88-90, GCSE Chemistry, Hodder, AQA
Concentrations of solutions, page 193, GCSE Combined Science Trilogy 1, Hodder, AQA
Concentrations, page 126, GCSE Combined Science; The Revision Guide, CGP, AQA
Concentrations, pages 118-120, GCSE Combined Science Trilogy; Chemistry, CGP, AQA
Concentrations, pages 129-135, GCSE Chemistry, CGP, AQA
Concentrations, pages 46, 47, GCSE Chemistry; The Revision Guide, CGP, AQA

Edexcel

Concentration, pages 20, 88, 197, GCSE Combined Science, Pearson Edexcel
Concentration, pages 24, 126, 164, GCSE Biology, Pearson, Edexcel
Concentration, pages 29, 44, 65, GCSE Chemistry; The Revision Guide, CGP, Edexcel
Concentration, pages 53, 112-113, GCSE Chemistry, Pearson, Edexcel
Concentration, pages 80, 81, 123, 124, 187, 188, GCSE Chemistry, CGP, Edexcel
Concentration, pages 92, 106, GCSE Combined Science; The Revision Guide, CGP, Edexcel
Concentration; effect on equilibrium, page 122, GCSE Combined Science; The Revision Guide, CGP, Edexcel
Concentration; effect on equilibrium, page 60, GCSE Chemistry; The Revision Guide, CGP, Edexcel
Concentration; effect on equilibrium, pages 173, 203, GCSE Chemistry, CGP, Edexcel
Concentration; effect on rate, pages 129, 132, GCSE Combined Science; The Revision Guide, CGP, Edexcel
Concentration; effect on rate, pages 232, 235, 236, GCSE Chemistry, CGP, Edexcel
Concentration; effect on rate, pages 78, 81, GCSE Chemistry; The Revision Guide, CGP, Edexcel

OCR

Concentration (effect on reaction rate), page 131, Gateway GCSE Combined Science; The Revision Guide, CGP, OCR
Concentration, pages 44, 63, 64, GCSE Chemistry; The Revision Guide, CGP, OCR Gateway
Concentration; acids, pages 118-119, 274-275, Gateway GCSE Chemistry, Oxford, OCR
Concentration; calculations, pages 164-165, Gateway GCSE Chemistry, Oxford, OCR
Concentration; effect on equilibrium, page 74, GCSE Chemistry; The Revision Guide, CGP, OCR Gateway
Concentration; effect on rate, page 71, GCSE Chemistry; The Revision Guide, CGP, OCR Gateway
Concentration; equilibrium position, page 188-189, 190, Gateway GCSE Chemistry, Oxford, OCR
Concentration; reaction rates, pages 178-179, Gateway GCSE Chemistry, Oxford, OCR
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