# What is the definition of standard temperature and pressure (STP)?

##### 1 Answer

Oct 5, 2017

**Standard Temperature and Pressure** is defined by IUPAC as:

#0^@ "C"# and#"1.000 bar"# after 1982#0^@ "C"# and#"1.000 atm"# before 1982

The numerical difference is that one obtains a molar volume of ideal gas to be:

#"22.414 L/mol"# at#0^@ "C"# and#"1.000 atm"# .#"22.711 L/mol"# at#0^@ "C"# and#"1.000 bar"# .

and the universal gas constant is:

#"0.082057 L"cdot"atm/mol"cdot"K"# at#0^@ "C"# and#"1 atm"# .#"0.083145 L"cdot"bar/mol"cdot"K"# at#0^@ "C"# and#"1 bar"# .

where

#"1.000 bar"# #=# #"100000 Pa"# #"1.000 atm"# #=# #"101325 Pa"#

*As such, you should always specify which pressure your STP uses for your textbook for your course.*

Note that