Answer:
.573 moles
Explanation: assuming 8.562 LITER volume:
Ideal gas law
PV = n RT the gas constant to be used has to match the units of the other parameters R = .082057 L-atm/mol-K
T must be in K units
1.5 (8.562) = n * (.082057)(273.15)
n=.573 moles