Two closed identical conducting containers are found in the laboratory of an old…

Two closed identical conducting containers are found in the laboratory of an old scientist. For the verification of the gas some experiments are performed on the two boxes and the results are noted.

Experiment 1: When the two containers are weighed              WA = 225 g, WB = 160 g and mass of evacuated container WC=100 g.
Experiment 2: When the two containers are given same amount of heat same temperature rise is recorded. The pressure change found are \(\Delta P_{A}\) = 2.5 atm, \(\Delta P_{B}\) = 1.5 atm
Required data for unknown gas:
Mono (molar mass)
 He Ne Ar Kr Xe Rd
 4 g 20 g 40 g 84 g 131 g       222 g
Dia (molar mass)
 H2 F2 N2 O2 Cl2
 2 g 19 g 28 g 32 g 71 g
 The initial internal energy of the gas in container 'A', if the containers were at room temperature 300 K initially