standard temperature and pressure: meaning, definition, pronunciation and examples

The most common definition (especially in chemistry) is 0 degrees Celsius (273.15 Kelvin) and 1 standard atmosphere (101.325 kilopascals). However, other standards exist, such as 20°C for some engineering applications.

They are often used interchangeably, but 'standard conditions' (SC) can sometimes refer to a different set of reference values (like 15°C and 101.325 kPa in the natural gas industry). Always check the specific definition in your context.

It provides a consistent reference point. Gases expand with heat and are compressed by pressure, so measuring volume without stating the conditions is meaningless. STP allows scientists and engineers worldwide to compare 'apples to apples'.

It is primarily a concept for gases, as their volume is highly dependent on temperature and pressure. For solids and liquids, 'standard state' is a more relevant concept, which may include specific temperature, pressure, and concentration.

Standardised reference values for temperature and pressure used to define normal conditions for comparing measurements of gas properties, most commonly 0°C (273.

Standard temperature and pressure is usually technical in register.

Standard temperature and pressure: in British English it is pronounced /ˈstændəd ˌtemprətʃər ənd ˈpreʃə/, and in American English it is pronounced /ˈstændərd ˌtɛmp(ə)rətʃər ənd ˈprɛʃər/. Tap the audio buttons above to hear it.