Knowledge Organiser: Gas Pressure and Temperature

Pressure caused by particle-wall collisions
Higher T → faster particles → more frequent + harder collisions → higher pressure
As temperature rises at constant volume, pressure rises

p = F/A (Pa = N/m²)
T(K) = T(°C) + 273 (Edexcel: conversion only; Eduqas: also used inside gas-law calculations)
p₁V₁ = p₂V₂ (Boyle's law, constant temperature) — Physics only on AQA and Edexcel (14.19P); given as pV = constant on every board's equation sheet

Particle explanation: speed + frequency + force of collisions
Boyle's law calculations need no Kelvin conversion on any board; only Eduqas sets pressure-law calculations, which do
Absolute zero: particles at minimum KE, p = 0 theoretically
Don't confuse pressure increase with particles getting bigger

Using Celsius instead of Kelvin (Eduqas only): Eduqas pressure-law calculations must use temperature in Kelvin — convert by adding 273 to the Celsius value (0°C = 273 K). Boyle's law calculations, which are the only gas calculation on AQA, Edexcel, OCR A and OCR B, need no temperature conversion at all.
Incomplete particle explanation for pressure increase: Must state that particles move faster, collide more frequently with the walls, AND each collision exerts a greater force — all three points are needed
Confusing pressure and volume changes: At constant temperature, increasing volume decreases pressure (p₁V₁ = p₂V₂); at constant volume, increasing temperature increases pressure
Saying absolute zero means no energy: At absolute zero (−273°C / 0 K), particles have minimum kinetic energy — they do not stop completely in the classical model
Forgetting units for pressure: Pressure must be in Pascals (Pa) and volume in m³ for the standard gas equations — check units carefully before substituting

Gas Pressure & Temperature, Knowledge Organiser