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States of Matter & Gas Laws

Combined Gas Law

The relation linking pressure, volume and temperature for a fixed amount of gas undergoing a change of state.

Formula / equation p₁V₁ / T₁ = p₂V₂ / T₂
Unit Various

In depth

It merges Boyle's, Charles's and Gay-Lussac's laws into one expression for a closed system where the amount of gas is unchanged. Temperature must always be in kelvin, and any consistent set of pressure and volume units may be used since they cancel.

Examples in the real world

A weather balloon rising from 100 kPa and 293 K to 25 kPa and 220 K expands to about three times its volume.