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Gas
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===Gas Volume and Mass===
: At [[Standard Temperature and Pressure]] (20°C and 101,000Pa) the [[Volume (Space)|volume]] of one [[mole]] of [[gas]] is 24 dm<sup>3</sup>.
: The [[Volume (Space)|volume]] of [[gas]] required or [[product|produced]] in a [[Chemical Reaction|chemical reaction]] can be calculated from the [[mass]] of the [[gas]] and its [[Relative Formula Mass]].
====Example Calculations====
Since 1 [[mole]] of gas is 24 dm<sup>3</sup> then 12dm<sup>3</sup> is 0.5 [[mole]]s of [[gas]], 6dm<sup>3</sup> is 0.25dm<sup>3</sup>.
{| class="wikitable"
|-
| style="height:20px; width:200px; text-align:center;" |'''Calculate the [[Volume (Space)|volume]] of 4g of [[Hydrogen]] [[gas]].'''
| style="height:20px; width:200px; text-align:center;" |'''Calculate the [[Volume (Space)|volume]] of 8g of [[Oxygen]] [[gas]].'''
| style="height:20px; width:200px; text-align:center;" |'''Calculate the [[Volume (Space)|volume]] of 20g of [[Methane]] [[gas]].'''
|-
| style="height:20px; width:200px; text-align:center;" |1.'''Find the [[Relative Formula Mass]] of the [[gas]].'''
[[Chemical Formula]] of [[Hydrogen]] = H<sub>2</sub>
[[Relative Atomic Mass]] of [[Hydrogen]] = 1g
[[Relative Formula Mass]] of H<sub>2</sub> = 2g
| style="height:20px; width:200px; text-align:center;" |1.'''Find the [[Relative Formula Mass]] of the [[gas]].'''
[[Chemical Formula]] of [[Oxygen]] = O<sub>2</sub>
[[Relative Atomic Mass]] of [[Oxygen]] = 16g
[[Relative Formula Mass]] of O<sub>2</sub> = 32g
| style="height:20px; width:200px; text-align:center;" |1.'''Find the [[Relative Formula Mass]] of the [[gas]].'''
[[Chemical Formula]] of [[Methane]] = CH<sub>4</sub>
[[Relative Atomic Mass]] of [[Hydrogen]] = 1g
[[Relative Atomic Mass]] of [[Carbon]] = 12g
[[Relative Formula Mass]] of CH<sub>4</sub> = 16g
|-
| style="height:20px; width:200px; text-align:center;" |'''2. Calculate the number of [[mole]]s of [[gas]].'''
1 [[mole]] = 2g
No. [[Mole]]s = <math>\frac{Mass}{M_r}</math>
No. [[Mole]]s = <math>\frac{4}{2}</math>
No. [[Mole]]s = 2mol
| style="height:20px; width:200px; text-align:center;" |'''2. Calculate the number of [[mole]]s of [[gas]].'''
1 [[mole]] = 32g
No. [[Mole]]s = <math>\frac{Mass}{M_r}</math>
No. [[Mole]]s = <math>\frac{8}{32}</math>
No. [[Mole]]s = 0.25 mol
| style="height:20px; width:200px; text-align:center;" |'''2. Calculate the number of [[mole]]s of [[gas]].'''
1 [[mole]] = 16g
No. [[Mole]]s = <math>\frac{Mass}{M_r}</math>
No. [[Mole]]s = <math>\frac{20}{16}</math>
No. [[Mole]]s = 1.25 mol
|-
| style="height:20px; width:200px; text-align:center;" |'''3. Find the [[Volume (Space)|volume]] in dm<sup>3</sup>.'''
[[Volume (Space)|Volume]] = 24 x (number of moles)
[[Volume (Space)|Volume]] = 24 x (2)
[[Volume (Space)|Volume]] = 48dm<sup>3</sup>
| style="height:20px; width:200px; text-align:center;" |'''3. Find the [[Volume (Space)|volume]] in dm<sup>3</sup>.'''
[[Volume (Space)|Volume]] = 24 x (number of moles)
[[Volume (Space)|Volume]] = 24 x (0.25)
[[Volume (Space)|Volume]] = 6dm<sup>3</sup>
| style="height:20px; width:200px; text-align:center;" |'''3. Find the [[Volume (Space)|volume]] in dm<sup>3</sup>.'''
[[Volume (Space)|Volume]] = 24 x (number of moles)
[[Volume (Space)|Volume]] = 24 x (1.25)
[[Volume (Space)|Volume]] = 30dm<sup>3</sup>
|}