Chemistry · Ch 5 — States of Matter
Gay Lussac's Law (Pressure-Temperature Relationship)
Gay Lussac's Law (Pressure-Temperature Relationship)
Pressure and temperature at constant volume
Anyone who has checked a car tyre knows the everyday version of this law: tyre pressure, nearly constant most of the time, rises noticeably on a hot day and can even burst the tyre, while on a cold morning the same tyre reads a lower pressure. Joseph Gay Lussac worked out the precise mathematical relationship behind this: at constant volume, the pressure of a fixed amount of gas varies directly with its (absolute) temperature — this is Gay Lussac's Law.
This relationship is not independent — it can be derived by combining Boyle's law and Charles' law, since both link the same underlying , , behaviour of a gas.
The isochore …
What this figure shows. A pale-yellow-shaded graph with vertical axis 'Pressure (bar)' (upward arrow) and horizontal axis 'Temperature (K)' (rightward arrow, marked 0, 100, 200, 300, 400). Four straight lines (isochores) fan out from near the origin, labelled V1 (steepest, topmost, blue), V2 (red), V3 (green), V4 (shallowest, cyan), with the relation 'V1 < V2 < V3 < V4' written above them — each line's lower portion (near the origin) is dashed/dotted where extrapolated, showing pressure directly proportional to absolute temperature at constant volume, with a smaller consta …