Answer:
the molar gas constant "R", has the value 8.3143 J/mol K,
and the temperature "T", is in Kelvin.
Since the joule is the kg-m2/s2, the molar mass must be in kg/mol
vrms = (the square root of)3RT/M,
vrms CO = [(3)(255K)(8.3143 J/mol K) / (0.02801 kg/mol)]^1/2 = 477 m/sec
vrms CO2 = [(3)(255K)(8.3143 J/mol K) / (0.04401 kg/mol)]^1/2 = 380 m/sec
vrms SO3 = [(3)(255K)(8.3143 J/mol K) / (0.08006 kg/mol)]^1/2 = 282 m/sec
K.E. = 1/2 (mass) (velocity)2 or
= 3/2 RT Joules/mole
= 1.5 (8.314 J/mol-K)(255K)
= 13.78 joules per mole
answer is: 13.8 J/mole is the average K.E. for any of the three gases
