Difference between revisions of "Gas"
(→Key Stage 4) |
(→Key Stage 4) |
||
Line 83: | Line 83: | ||
===Gas Volume and Mass=== | ===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> | ||
+ | |} |
Revision as of 14:09, 23 January 2019
Contents
Key Stage 2
Meaning
Gas is a state of matter that can change size and shape to fit any container.
About Gases
- Most gases are invisible but we can feel them.
- When the air moves we call it the wind.
|
Gases can be squashed into a smaller size. |
Examples of gas materials:
- Air (A mixture of gases, mostly nitrogen and oxygen)
- Steam
Key Stage 3
Meaning
Gas is a State of Matter in which the particles are separated by large distances and can move freely.
About Gases
Gas can be squashed into a smaller size because the particles are spread apart. |
Key Stage 4
Meaning
Gas is a State of Matter in which the particles are separated by large distances and can move freely.
About Gases
- When a substance is in its gaseous state it is always less dense than in its liquid or solid state due to the particles in a gas being spread far apart from each other.
- A substance which is gaseous at room temperature has a smaller force of attraction between particles than a substance which is liquid or solid at room temperature.
Particle Diagram | Particle Arrangement | Property |
Particles are free to move in all directions. | Gases fit the size of their container. | |
Gases fit the shape of their container. | ||
Convection happens most easily in gases. | ||
Particles are spread apart. | Gases can be compressed into a smaller volume. | |
Sound passes through gases slower than liquids and solids. | ||
Thermal Conduction is very poor in a gases. |
Gas Volume and Mass
- At Standard Temperature and Pressure (20°C and 101,000Pa) the volume of one mole of gas is 24 dm3.
- The volume of gas required or produced in a 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 dm3 then 12dm3 is 0.5 moles of gas, 6dm3 is 0.25dm3.
Calculate the volume of 4g of Hydrogen gas. | Calculate the volume of 8g of Oxygen gas. | Calculate the volume of 20g of Methane gas. |
1.Find the Relative Formula Mass of the gas.
Chemical Formula of Hydrogen = H2 Relative Atomic Mass of Hydrogen = 1g Relative Formula Mass of H2 = 2g |
1.Find the Relative Formula Mass of the gas.
Chemical Formula of Oxygen = O2 Relative Atomic Mass of Oxygen = 16g Relative Formula Mass of O2 = 32g |
1.Find the Relative Formula Mass of the gas.
Chemical Formula of Methane = CH4 Relative Atomic Mass of Hydrogen = 1g
Relative Formula Mass of CH4 = 16g |
2. Calculate the number of moles of gas.
1 mole = 2g No. Moles = \(\frac{Mass}{M_r}\) No. Moles = \(\frac{4}{2}\) No. Moles = 2mol |
2. Calculate the number of moles of gas.
1 mole = 32g No. Moles = \(\frac{Mass}{M_r}\) No. Moles = \(\frac{8}{32}\) No. Moles = 0.25 mol |
2. Calculate the number of moles of gas.
1 mole = 16g No. Moles = \(\frac{Mass}{M_r}\) No. Moles = \(\frac{20}{16}\) No. Moles = 1.25 mol |
3. Find the volume in dm3.
Volume = 24 x (number of moles) Volume = 24 x (2) Volume = 48dm3 |
3. Find the volume in dm3.
Volume = 24 x (number of moles) Volume = 24 x (0.25) Volume = 6dm3 |
3. Find the volume in dm3.
Volume = 24 x (number of moles) Volume = 24 x (1.25) Volume = 30dm3 |