For hydrogen molecule, how many mols of it are there in #"33.4 L"# at STP?
2 Answers
Feb 9, 2018
At STP, all gases have a molar volume of 22.4 L/mol
Feb 9, 2018
I got
If we ASSUME (!!!!) that hydrogen gas is an ideal gas, then we ASSUME that the ideal gas law works:
#PV = nRT#
#P# is pressure in#"atm"# or#"bar"# ...#V# is volume in#"L"# .#R = "0.083145 L"cdot"bar/mol"cdot"K"# #=# #"0.082057 L"cdot"atm/mol"cdot"K"# is the universal gas constant.#T# is the temperature in#"K"# .#n# is obviously the mols of IDEAL gas.
And so,
#n = (PV)/(RT)#
STP is defined since 1982 as
Before 1982,
#n = ("1 atm"cdot"33.4 L")/("0.082057 L"cdot"atm/mol"cdot"K" cdot "273.15 K")#
#=# #"1.49 mols"#
But since we're not old-timers who are stuck in the past, we look at AFTER 1982 to obtain:
#n = ("1 bar" cdot "33.4 L")/("0.083145 L"cdot"bar/mol"cdot"K" cdot "273.15 K")#
#=# #ulcolor(blue)"1.47 mols"#