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...