Besides atmospheres and pascals, which unit is commonly used for measuring pressure in gas law calculations?

Millimeters of mercury (mmHg) is indeed a commonly used unit for measuring pressure in gas law calculations. This unit originates from the way barometers historically measured atmospheric pressure, using a column of mercury. One mmHg approximates the pressure exerted at the base of a 1 millimeter high column of mercury at standard gravity. In terms of the relationship with other pressure units, 1 mmHg is equivalent to approximately 133.322 pascals, illustrating its relevance and utility in various contexts, especially in chemistry.

Using mmHg allows researchers and scientists to express pressures in a unit that feels intuitive when discussing atmospheric conditions, as well as in medical applications such as blood pressure measurements, where it is frequently encountered. Its widespread use across different fields of science reflects its practicality and historical significance in pressure measurement.