The ideal gas under STP is 22.4 L/mol. While the gas has a rule of P1V1/T1=P2V2/T2. So the volume under 101 kPa and 273 K is 0.2*22.4=4.48 L.
A. Smell (Oder) B. Color and D I’m pretty sure because the common properties are Color, Oder, Melting point, and boiling point
k=.240/(.4)^2=1.5 assuming [A]2 means [A] squared
1. (b) I hope this helps!