Answer
See the answer below.
Work Step by Step
a,b) Since $\sqrt{\bar{u^2}}=\sqrt{3RT/M}$
Ratio $T/M$ for flask A is $135.4\ K.mol/g$ and $6.78\ K.mol/g$ for B, so flask A has molecules with bigger rms speed and consequently bigger kinetic energy per molecule.
c,d) Since the volume is the same for both, $n\propto P/T$, and this ratio is $3.66×10^{-3}\ atm/K$ for flask A and $6.71×10^{-3}\ atm/K$ for B, therefore B has a greater number of molecules, and since it also has a gas with greater molecular weight, B has the bigger mass of gas.
