How many hydrogen molecules are in a 2 liter vessel if the mean square velocity

How many hydrogen molecules are in a 2 liter vessel if the mean square velocity of the molecules is 500 m / s and the pressure on the vessel walls is 103 Pa?

To find the required number of hydrogen molecules, we apply the formula: P = n * m0 * Vav ^ 2/3 = (N / V) * (M / Na) * Vav ^ 2/3 and N = 3 * P * V * Na / (M * Vcr ^ 2).

Data: P – pressure on the vessel walls (P = 10 ^ 3 Pa); V is the capacity of the vessel (V = 2 l = 2 * 10 ^ -3 m3); Na – Avogadro’s number (Na = 6.02 * 10 ^ 23 mol-1); M – molar mass (M = 2.016 * 10 ^ -3 kg / mol); Vav – mean square velocity (Vav = 500 m / s).

Calculation: N = 3 * 10 ^ 3 * 2 * 10 ^ -3 * 6.02 * 10 ^ 23 / (2.016 * 10 ^ -3 * 500 ^ 2) = 7.17 * 10 ^ 21 molecules.