The critical constants Pc and Tc for four gases are Gas Critical temp Critical press 153 K 50 bar 41 — States of Matter and Gaseous State Chemistry Question

Question

The critical constants Pc and Tc for four gases are Gas Critical temp Critical press $O_2$ 153 K 50 bar $Cl_2$ 417 K 76 bar $H_2$ 33.9 K 13.5 bar He 5.12 K 2.2 bar The gas with smallest value of van der Waal's constant b is