The force exerted by the weight of air above a given point is a critical parameter in chemical systems. This force, arising from the combined weight of all the gases in the air column above, directly influences chemical reactions and physical properties. For instance, the boiling point of a liquid is dependent on the surrounding pressure; a lower surrounding pressure results in a lower boiling point. As an example, water boils at a lower temperature at high altitudes where the surrounding parameter is reduced.
Understanding this force is fundamental to various chemical disciplines. In laboratory settings, accurate measurements of this parameter are essential for precise experimental control, especially when dealing with gas-phase reactions or processes involving volatile substances. Historically, the quantification of this parameter allowed for the development of standard conditions (STP) for comparing gas volumes and establishing relationships between pressure, volume, and temperature.