levo

Particle Model of Matter

Pressure in gases, volume and temperature

  • 3 things to know
  • Paper 1

Overview

What a change in pressure does to a gas, the direction of the force on a container wall, why pressure and volume change in opposite directions at constant temperature, the relationship pV = constant with its symbols, units and calculations, and what happens to a bubble of gas rising through a lake.

What you need to know

Answer each one before you reveal it.

Your recallNot started
Key term

Use the particle model to explain why increasing the volume of a gas at constant temperature lowers its pressure.

Key term

Explain why squeezing a gas into a smaller volume at constant temperature raises its pressure.

Key term

State the relationship between the pressure and the volume of a fixed mass of gas at constant temperature.

Questions from this subtopic

Each one with the model answer underneath.

  1. 1

    State the two things a change in pressure can do to a gas.

    Model answer

    It can compress the gas into a smaller volume or allow it to expand into a larger one.

  2. 2

    In which direction does the force produced by the pressure of a gas act on the wall of its container?

    Model answer

    At right angles to the surface of the wall.

  3. 3

    Use the particle model to explain why increasing the volume of a gas at constant temperature lowers its pressure.

    Model answer

    The same molecules are spread through a larger space, so they strike each unit of wall area less often and the pressure falls.

  4. 4

    Explain why squeezing a gas into a smaller volume at constant temperature raises its pressure.

    Model answer

    The molecules hit the walls more often in the smaller space, so the force on each unit of area is greater.

  5. 5

    Under what two conditions does the relationship pressure × volume = constant hold?

    Model answer

    For a fixed mass of gas kept at a constant temperature.

  6. 6

    State the relationship between the pressure and the volume of a fixed mass of gas at constant temperature.

    Model answer

    Pressure × volume stays constant, so if one of them doubles the other halves.

Other ways to work this

The same content, four other ways.

What is inside Levo

Six ways to work the same material.

1Closed book
2Open book
3Closed book

The 3-step method, run for you

Answer cold, learn it, then prove it stuck. Levo tracks the jump between your first attempt and your last.

Atomic Structure
Electricity
Energy
Forces

Cram a whole paper in one sitting

Sort every topic into what you know and what you do not, then drill only the weak ones.

A wave.
transverselongitudinalmechanical

Blank Blitz makes facts automatic

Rapid timed gap-fills on the terms and numbers you need to recall without thinking.

AA cloud of dust and gas in space.
BThe force of gravity pulls the material together.
CThe material is pulled together tightly enough for nuclei to fuse.

Build It gets the exam shape right

Assemble a full-mark answer from its marking points, in the order an examiner wants them.

Moon means a natural body orbiting a planet.
TrueFalse

Test It catches misconceptions

Spot the fault in a statement. The traps are the mistakes students actually make.

721941163128510

Brain Breaks between sessions

Short focus games to reset attention, so the next set lands better than the last.

Every question in Particle Model of Matter, on a schedule.

Attempt a question from memory, write the correct version, then attempt it again. Levo records the jump between your first attempt and your last, and brings each question back on the day you are due to forget it.

Or £46 a year, about £3.83 a month. Cancel anytime.