Mol STP Chemistry

Question

Calculate the volume, in liters, occupied by 1.45 mol of oxygen gas at STP.

Answer 1

When at STP, an easier way to find the volume is knowing that 1 mole of any ideal gas occupies 22.4 liters.  Thus,

1.45 moles x 22.4 liters/mole = 32.48 liters = 32.5 liters.

Answer 2

Given the conditions, we can use the ideal gas law equation to solve. STP is standard temperature and pressure, or 273 K and 1 atm.

 

PV = nRT

(1 atm)V = (1.45 moles)(0.08206 atm.L/mol/K)(273 K)

V = [(1.45 moles)(0.08206 atm.L/mol/K)(273 K)]/(1 atm)

   = 32.5 L