10 kg of air expands adiabatically. The gas temperature varies from 600

10 kg of air expands adiabatically. The gas temperature varies from 600 to 300 K. Determine the work of air expansion (air is considered a diatomic gas, μ = 29 g / mol).

The first law of thermodynamics:

dU = Q – A.

For an adiabatic process Q = 0, then:

dU = -A.

U = (i / 2) * (m * R * T) / M.

dU = (i / 2) * (m * R * (T1 – T2)) / M =

= (2/2) * (10 * 8.31 * (600 – 300)) / (29 * 10 ^ (- 3)) = 860 * 10 ^ 3 J.

Answer:

dU = A = 860 kJ.