The average kinetic energy of the molecules in a gas sample depends only on the temperature, T. But given the same kinetic energies, a lighter molecule will move faster than a heavier molecule.where R=8.314 J/(mol·K) and ℳ is molar mass in kilograms per mole. Note that a joule is the same as a kg·m2/s2. What is the rms speed of Cl2 molecules at 443 K? What is the rms speed of He atoms at 443 K?
What is the rms speed of Cl2 molecules at 443 K
molar mass of Cl2 = 71 g / mole = 0.071 kg / mole
rms speed of Cl2 = srt (3RT / M) = sqrt (3 * 8.314 * 443 / 0.071) = 394.5 m / s
What is the rms speed of He atoms at 443 K?
molar mass of He = 4.0 g / mole = 0.004 kg / mole
rms speed of He = srt (3RT / M) = sqrt (3 * 8.314 * 443 / 0.004) = 1662 m / s
as He is lighter element in compare to Cl2 and hence rms speed of He is higher in compare to Cl2.
The average kinetic energy of the molecules in a gas sample depends only on the temperature,...