(0.0821 L•atm/(mol•K)) × (1,000.0/1.000 mL/L) = 82.1 mL•atm/(mol•K)
(82.1 mL•atm/(mol•K)) × (101,325/1.000 Pa/atm) = 83,187,825 mL•Pa/(mol•K)
(83,187,825 mL•Pa/(mol•K)) × (1.00/22.4 mol/g) = 371,374.21875 mL•Pa/(g•K)
Round this down to 3 significant digits and rewrite in scientific notation:
371,374.21875 mL•Pa/(g•K) ≈ 371,000 mL•Pa/(g•K)
… ≈ 3.71 × 10³ mL•Pa/(g•K)