This how it works covers How Temperature and Pressure Are Linked (Absolute Temperature) within Gas Pressure & Temperature for GCSE Physics. Revise Gas Pressure & Temperature in Particle Model for GCSE Physics with 19 exam-style questions and 30 flashcards. This topic appears regularly enough that it should still be part of a steady revision cycle. It is section 5 of 12 in this topic. Use this how it works to connect the idea to the wider topic before moving on to questions and flashcards.
⚙️ How Temperature and Pressure Are Linked (Absolute Temperature)
For a fixed mass of gas at constant volume, pressure is proportional to absolute temperature:
p ∝ T (constant volume)
This means if you double the absolute temperature (in Kelvin), you double the pressure. But temperature must be in Kelvin, not Celsius:
- Absolute zero (0 K = −273°C): The temperature at which particles have minimum kinetic energy and gas pressure would theoretically be zero.
- Conversion: T (K) = T (°C) + 273
- So 100°C = 373 K, and 0°C = 273 K
Why Kelvin? At −273°C, particles theoretically stop moving (minimum possible kinetic energy). This is the lowest possible temperature — absolute zero. The Kelvin scale starts here, which is why pressure is directly proportional to Kelvin temperature.
Practice questions for Gas Pressure & Temperature
A sealed gas container is heated. What happens to the pressure of the gas inside?
A sealed gas cylinder is heated. Explain, using particle theory, why the pressure of the gas increases when the temperature increases.