Definition

Noun: 1. A specific unit of atmospheric pressure: Standard pressure is defined as the pressure that will support a column of mercury 760 millimeters high at sea level at a temperature of 0 degrees Celsius. It is a precisely defined reference value used in science and engineering.

Usage

• Standard pressure is a fundamental constant in fields like physics, chemistry, and meteorology. It is used as a baseline for defining other units (like the standard atmosphere) and for reporting measurements under normalized conditions.
• It is often used to specify the "standard" conditions (Standard Temperature and Pressure, or STP) under which the properties of gases are compared.

Examples

• In the laboratory, the volume of the gas was measured at standard pressure and 273 Kelvin.
• One atmosphere (1 atm) is defined as being equal to standard pressure.
• The experiment requires the reactants to be at standard pressure for accurate comparison.

Advanced Usage

• "Standard Temperature and Pressure (STP)": A standard set of conditions for experimental measurements, defined as a temperature of 0°C (273.15 K) and a pressure equal to standard pressure (1 atm or 101.325 kPa).
  • The molar volume of an ideal gas at STP is 22.4 liters.

Variants and Related Words

• Atmosphere (atm) (n): A unit of pressure approximately equal to standard pressure. (1 atm = 101.325 kPa).
• Pressure (n): The continuous physical force exerted on or against an object by something in contact with it.
• Bar (n): A metric unit of pressure, where 1 bar is slightly less than standard pressure (1 bar = 100 kPa).

Synonyms

• Normal pressure: (In specific technical contexts) Can be used interchangeably with standard pressure.
• 760 mmHg: A direct description of the definition (millimeters of mercury).
• 1 atmosphere (1 atm): The unit defined by this pressure.

Related Terms and Contexts

• Pascal (Pa) / Kilopascal (kPa): The SI unit of pressure. Standard pressure is equal to 101,325 pascals or 101.325 kilopascals.
• Torr: A unit of pressure based on millimeters of mercury (mmHg). Standard pressure is equal to 760 torr.

Noun

1. a unit of pressure: the pressure that will support a column of mercury 760 mm high at sea level and 0 degrees centigrade