New
New
Year 10
AQA
Higher

Gas volumes

I can calculate the mass and the volume of a gas reactant/product given a balanced equation.

New
New
Year 10
AQA
Higher

Gas volumes

I can calculate the mass and the volume of a gas reactant/product given a balanced equation.

Lesson details

Key learning points

  1. Equal amounts in moles of gases occupy the same volume under the same conditions of temperature and pressure.
  2. The volume of one mole of any gas at room temperature and pressure (20℃ and 1 atmosphere pressure) is 24 dm³.
  3. The volumes of gaseous reactants and products can be calculated from the balanced equation for the reaction.
  4. If moles of gas are known, its density can be calculated using molar gas volume and the relationship mass = RFM x moles.

Common misconception

Pupils sometimes rush these calculations and forget to take note of the units.

Remind pupils that units provide the comparison standard for values. Much practice ensuring the correct molar gas volume value is used in calculations is necessary.

Keywords

  • Volume - is how much 3D space matter occupies. It is usually measured in cm³.

  • Moles - of something is 6.02 × 10²³ of it. The mass of a mole of a substance is its relative mass expressed in grams.

  • Molar gas volume - is the volume occupied by one mole of any gas. It is equal to 24 dm³ or 24 000 cm³ at room temperature and pressure.

  • Stoichiometry - refers to the molar ratio of the reactants and products in a chemical reaction.

  • Density - is a property of a substance and is its mass divided by its volume.

A large variety of practical/industrial applications can be used to build science capital in this lesson. Consider calculations related to: vehicle airbags, photosynthesis, combustion or the production of industrial gases. Perhaps also consider looking at Zeppelins - the Hindenburg and blimps.
Teacher tip

Equipment

None required.

Licence

This content is © Oak National Academy Limited (2024), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).

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6 Questions

Q1.
Use the particle model to describe how particles are arranged and behave in a gas.
They vibrate in fixed positions
Correct answer: They are widely spaced and randomly arranged
Correct answer: They are free to move in any direction
They are randomly arranged and loose together
Q2.
How many cm³ in 1 dm³?
10
100
Correct answer: 1000
10 000
Q3.
State the equation linking mass, volume and density.
Correct answer: density = mass ÷ volume
mass = density ÷ volume
volume = mass ÷ density
density = mass × volume
Q4.
Convert 10 cm³ into dm³.
Correct Answer: 0.01 dm³, 0.01, 0.01dm³
Q5.
Calculate the volume of a cube with a side length of 2 cm. Give your answer in dm³.
8
0.8
0.08
Correct answer: 0.008
Q6.
Convert 2 dm³ into m³.
Correct Answer: 0.002 m³, 0.002m³, 0.002

6 Questions

Q1.
Match the following terms to their definitions.
Correct Answer:Molar gas volume,The volume occupied by 1 mole of a gas

The volume occupied by 1 mole of a gas

Correct Answer:Mole,Unit for amount of substance

Unit for amount of substance

Correct Answer:Density,A measure of how much matter is located in a particular volume

A measure of how much matter is located in a particular volume

Correct Answer:Volume,How much 3D space matter occupies

How much 3D space matter occupies

Q2.
Which of the following factors affect the volume of a gas?
Correct answer: Temperature
Correct answer: Pressure
Catalyst
Relative mass
Q3.
At room temperature and pressure, 1 mole of any gas occupies a volume of dm³.
Correct Answer: 24, 24.0
Q4.
State the equation linking molar gas volume, moles and volume of gas.
Correct answer: volume of gas = moles × molar gas volume
moles = volume of gas × molar gas volume
volume of gas = moles ÷ molar gas volume
moles = molar gas volume ÷ volume of gas
Q5.
Calculate the density of a gas with a mass of 0.060 g and a volume of 24 dm³. Give your answer in g/cm³.
Correct Answer: 1440 g/cm³, 1440g/cm³, 1,440 g/cm³, 1,440g/cm³, 1440
Q6.
Calculate the volume of 3.0 mol of hydrogen gas at room temperature and pressure.
Correct answer: 72 dm³
72 cm³
72,000 dm³
Correct answer: 72,000 cm³