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==Key Stage 3==
===Meaning===
[[Molarity]] is the a[[unit]]s of [[concentration]] of a [[solution]]s.
===About Molarity===
: The [[molarity]] of [[Stomach Acid]] is around 0.16 '''Molar''' (0.16M).
: The [[molarity]] of [[Battery Acid]] can be as much as 5.2 '''Molar''' (5.2M).
==Key Stage 4==
===Meaning===
[[Molarity]] is a [[unit]] of [[concentration]] of [[solution]]s in mol/dm<sup>3</sup>.
===About Molarity===
: [[Molarity]] is shortened with an upper case '''M'''.
: [[Molarity]] is the [[ratio]] of the number of [[mole]]s of a [[solute]] to the [[Volume (Space)|volume]] of [[solvent]].
: When [[molarity]] is used to describe a [[solution]] it may be referred to as '''molar''', eg. a 0.5 '''molar''' [[solution]] of [[Sodium Chloride]].
: Bottles containing [[acid]] and [[alkali]] usually have their [[Molarity]] stated on the side. The more [[concentrated]] the higher the [[molarity]].
===Equation===
'' '''concentration (mol/dm<sup>3</sup>)''' '' = <math>\frac{Moles (mol)}{volume (dm^3)}</math>
Where:
: Moles = The number of [[mole]]s of the [[solute]]. Found by dividing the [[mass]] in [[gram]]s by the [[Relative Formula Mass|relative formula mass]].
: volume = The [[Volume (Space)|volume]] of [[solvent]].
{| 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;" |
'''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]] = 73g
[[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{73}{36.5}}</math>
Number of [[Mole]]s = 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{2}{0.4}</math>
'' '''concentration''' '' = 5mol/dm<sup>3</sup> = 5M
|}