Compute the root-mean-square speed

Question

Compute the root-mean-square speed of Ar molecules in a sample of argon gas at a temperature of 112°C.

Answer 1

Equation is root-mean-squared speed = √(3RT/M) where R is gas constant 8.314, T is Kelvin temp, and M is molar mass in Kg/mole. For argon, M = (39.95 g/mol) /1000 = 0.03995 kg/mol. The rms speed = [3 (8.314) (112 +273K) /0.03995]^1/2 = √240,400 = 490. m/s.