Pascal
Definition and meaning of Pascal in chemistry.
The pascal is the derived standard International System of Units (SI) unit of pressure, internal pressure, stress, and Young's modulus. It is defined as one newton of force applied uniformly over an area of one square meter.
In more detail
Because a single pascal is a very small amount of pressure, measurements in chemistry and atmospheric science are often reported in kilopascals or megapascals. Standard atmospheric pressure is exactly 101.325 kilopascals. The pascal replaces older units like atmospheres and torr in strict SI usage, though those older units remain common in traditional laboratory settings. Using pascals ensures consistency when calculating thermodynamic properties in standard chemical equations.
Key facts
| Field | Physical Chemistry |
|---|---|
| Unit Symbol | Pa |
| Base Units | kg / (m s^2) |
Standard atmospheric pressure at sea level is approximately 101,325 pascals.
Frequently asked questions
How many pascals are in one atmosphere?
There are exactly 101,325 pascals in one standard atmosphere (atm).