Calculate the total internal energy of the N2 nitrogen gas molecules moving at an average speed of 450 m/s. Assume ideal gas behavior.

Answer 1

In an ideal gas, we can consider the internal energy to be equal to the kinetic energy since the particles of gas do not interact.

KE = 1/2 mv2

m = mass in kg

v = velocity in m/s

1 mol N₂ = 28 g = 0.028 kg

KE = 1/2 (0.028 kg)(450 m/s)²

KE = 2835 kg m² /s² = 2835 J / mole of N₂

1 mol = 6.02x10² molecules, so KE per molecule = 2835 J/mol x 1 mol/6.02x10²³ molecules = 4.71x10^-21 J

Internal energy of the N₂ molecules = 4.71x10^-21 J / molecule