DP Physics Questionbank
3.2 – Modelling a gas
Description
Nature of science:
Collaboration: Scientists in the 19th century made valuable progress on the modern theories that form the basis of thermodynamics, making important links with other sciences, especially chemistry. The scientific method was in evidence with contrasting but complementary statements of some laws derived by different scientists. Empirical and theoretical thinking both have their place in science and this is evident in the comparison between the unattainable ideal gas and real gases. (4.1)
Understandings:
- Pressure
- Equation of state for an ideal gas
- Kinetic model of an ideal gas
- Mole, molar mass and the Avogadro constant
- Differences between real and ideal gases
Applications and skills:
- Solving problems using the equation of state for an ideal gas and gas laws
- Sketching and interpreting changes of state of an ideal gas on pressure–volume, pressure–temperature and volume–temperature diagrams
- Investigating at least one gas law experimentally
Guidance:
- Students should be aware of the assumptions that underpin the molecular kinetic theory of ideal gases
- Gas laws are limited to constant volume, constant temperature, constant pressure and the ideal gas law
- Students should understand that a real gas approximates to an ideal gas at conditions of low pressure, moderate temperature and low density
Data booklet reference:
Theory of knowledge:
- When does modelling of “ideal” situations become “good enough” to count as knowledge?
Utilization:
- Transport of gases in liquid form or at high pressures/densities is common practice across the globe. Behaviour of real gases under extreme conditions needs to be carefully considered in these situations.
- Consideration of thermodynamic processes is essential to many areas of chemistry (see Chemistry sub-topic 1.3)
- Respiration processes (see Biology sub-topic D.6)
Aims:
- Aim 3: this is a good topic to make comparisons between empirical and theoretical thinking in science
- Aim 6: experiments could include (but are not limited to): verification of gas laws; calculation of the Avogadro constant; virtual investigation of gas law parameters not possible within a school laboratory setting
Directly related questions
- 18M.2.SL.TZ2.2b.ii: Explain, in terms of molecular motion, this change in pressure.
- 18M.2.SL.TZ2.2b.i: Calculate, in Pa, the new pressure of the gas.
- 18M.2.SL.TZ2.2a.iii: Calculate, in J, the internal energy of the gas.
- 18M.2.SL.TZ2.2a.ii: Calculate the number of atoms in the gas.
- 18M.2.SL.TZ2.2a.i: State what is meant by an ideal gas.
- 18M.1.HL.TZ2.9: Q and R are two rigid containers of volume 3V and V respectively containing molecules of the same...
- 18M.2.SL.TZ1.2c: Explain, with reference to the kinetic model of an ideal gas, how an increase in temperature of...
- 18M.2.SL.TZ1.2b.ii: Calculate the average kinetic energy of the particles of the gas.
- 18M.2.SL.TZ1.2a: Calculate the pressure of the gas.
- 18M.2.HL.TZ1.2b.ii: Determine, in kJ, the total kinetic energy of the particles of the gas.
- 18M.1.SL.TZ1.12: A sealed cylinder of length l and cross-sectional area A contains N molecules of an ideal gas at...
- 18M.1.SL.TZ1.10: A fixed mass of an ideal gas is trapped in a cylinder of constant volume and its temperature is...
- 17N.1.SL.TZ0.9: What does the constant n represent in the equation of state for an ideal gas pV = nRT? A. The...
- 17N.1.SL.TZ0.11: Under what conditions of pressure and temperature does a real gas approximate to an ideal gas?
- 17N.1.HL.TZ0.12: Unpolarized light of intensity I0 is incident on a polarizing filter. Light from this filter is...
- 17M.3.SL.TZ1.1d: The cross-sectional area of the tube is 1.3 × 10–3\(\,\)m2 and the temperature of air is 300 K....
- 17M.3.SL.TZ1.1c: Outline how the results of this experiment are consistent with the ideal gas law at constant...
- 17M.3.SL.TZ1.1a: The student measured the height H of the air column and the corresponding air pressure p. After...
- 17M.2.HL.TZ2.5c.ii: The experiment was carried out at a temperature of 18 °C. The volume of cylinder B was 1.3 x 10–5...
- 17M.2.SL.TZ2.4c: Rutherford and Royds expected 2.7 x 1015 alpha particles to be emitted during the experiment. The...
- 17M.1.HL.TZ2.10: An ideal gas has a volume of 15 ml, a temperature of 20 °C and a pressure of 100 kPa. The volume...
- 17M.1.SL.TZ2.12: A sealed container contains a mixture of oxygen and nitrogen gas.The...
- 17M.1.SL.TZ1.15: Two pulses are travelling towards each other. What is a possible pulse shape when the pulses...
- 17M.1.SL.TZ1.12: A fixed mass of an ideal gas in a closed container with a movable piston initially occupies...
- 17M.1.SL.TZ1.11: A thin-walled cylinder of weight W, open at both ends, rests on a flat surface. The cylinder has...
- 16N.2.HL.TZ0.3b: 0.46 mole of an ideal monatomic gas is trapped in a cylinder. The gas has a volume of 21 m3 and a...
- 16N.1.SL.TZ0.12: The pressure of a fixed mass of an ideal gas in a container is decreased at constant temperature....
- 16N.1.SL.TZ0.11: An ideal gas of N molecules is maintained at a constant pressure p. The graph shows how the...
- 16M.1.SL.TZ0.12: Under what conditions of density and pressure is a real gas best described by the equation of...
- 16M.1.SL.TZ0.11: Which of the following is not an assumption of the kinetic model of ideal gases? A. All...
- 15M.1.SL.TZ1.11: In the kinetic model of an ideal gas, which of the following is not assumed? A. The molecules...
- 15M.1.HL.TZ1.8: A fixed mass of an ideal gas has a constant volume. Two quantities, R and S, of the gas vary as...
- 15M.1.HL.TZ1.9: A fixed mass of an ideal gas undergoes an isochoric (isovolumetric) change. This increases the...
- 15M.1.SL.TZ1.9: What is the definition of the mole? A. The amount of substance that has the same mass as...
- 15M.1.SL.TZ2.11: Which of the following is an assumption of the kinetic model of an ideal gas? A. The gas is at...
- 14M.1.SL.TZ2.12: An ideal gas is contained in a thermally insulated cylinder by a freely moving piston. The gas...
- 14M.1.HL.TZ2.11: Two containers, X and Y, are each filled by an ideal gas at the same temperature. The volume of Y...
- 15N.1.HL.TZ0.8: An ideal gas and a solid of the same substance are at the same temperature. The average kinetic...
- 14N.1.HL.TZ0.8: What are the conditions of temperature and pressure at which the behaviour of a real gas...
- 11N.1.HL.TZ0.12: A fixed mass of an ideal gas is at temperature T. The pressure is doubled and the volume is...
- 11M.1.SL.TZ2.11: The volume of an ideal gas in a container...
- 11M.1.SL.TZ2.9: The energy of the molecules of an ideal gas...
- 13M.2.HL.TZ1.12b: The graph shows how the pressure P of a sample of a fixed mass of an ideal gas varies with volume...
- 12M.2.SL.TZ2.4b: Argon behaves as an ideal gas for a large range of temperatures and pressures. One mole of argon...
- 12M.2.SL.TZ2.4c: At the temperature of 350 K, the piston in (b) is now freed and the argon expands until its...
- 12M.2.SL.TZ2.4a: State two assumptions of the kinetic model of an ideal gas.
- 11M.2.SL.TZ2.3b: Describe, with reference to the energy of the molecules, the difference in...
- 11M.2.SL.TZ2.3c: A piece of iron is placed in a kiln until it reaches the temperature θ of the...
- 13N.2.HL.TZ0.4a: Describe how the ideal gas constant R is defined.
- 13N.2.HL.TZ0.4b: Calculate the temperature of 0.100 mol of an ideal gas kept in a cylinder of volume 1.40×10–3 m3...
- 09M.1.SL.TZ1.11: In the kinetic model of an ideal gas, it is assumed that A. the forces between the molecules...
- 10M.1.HL.TZ1.13: The behaviour of a monatomic gas such as helium will approximate to that of an ideal gas when it...
- 10N.1.SL.TZ0.11: Which of the following is an assumption made in the kinetic model of ideal gases? A. ...
- 10N.1.HL.TZ0.11: The graph shows the variation with absolute temperature \(T\) of the pressure \(p\) of a fixed...
- 10M.1.SL.TZ1.10: The mole is defined as A. \(\frac{1}{{12}}\) the mass of an atom of the isotope...
- 09N.1.HL.TZ0.12: The behaviour of real gases is different from that predicted for ideal gases. Which of the...
