Question

The molar masses for 235UF6 and 238UF6 molecules are 0.349 kg/mol and 0.352 kg/mol, respectively. If uranium hexafluoride acts as an ideal gas, what is the ratio of the root-mean-square speed of 235UF6 molecules to that of 238UF6 molecules if the temperature is uniform

Answer 1

0.5908 : 0.5933

Step-by-step explanation:

vrms=√3RTM

where vrms is the root-mean-square of the velocity, Mm is the molar mass of the gas in kilograms per mole, R is the molar gas constant, and T is the temperature in Kelvin.

235UF6

Mm = 0.349 kg/mol

Vrms = √3(0.349) (R)(T)

238UF6

Mm = 0.352 kg/mol

Vrms = √3(0.352) (R)(T)

235UF6 : 238UF6

√3(0.349) (R)(T) : √3(0.352) (R)(T)

√0.349 : √0.352

0.5908 : 0.5933