Why is 22.4 liters called the molar volume of a gas?

1 Answer

The Molar Volume of an ideal gas at STP, which we define to be #0^@ "C"# and #"1 atm"# arbitrarily (because we're old-fashioned and stuck in 1982) is #"22.411 L/mol"#.

To calculate this we can use the Ideal gas law of #PV=nRT#

At STP (Standard Temperature and Pressure), we CHOSE:
#P = "1 atm"#
#V = ?#
#n = "1 mol"#
#R = "0.082057 L"cdot"atm/mol"cdot"K"#
#"T = 273.15 K"#

#V = (nRT)/P#

#= (1 cancel("mol")) (0.082057 (cancel("atm")cdot"L")/(cancel("mol")cdotcancel("K")))(273.15cancel("K"))/(1 cancel("atm"))#

#=# #"22.411 L"#

This is the volume of one mole of ideal gas at STP, in 1982 or before...