Question

Ammonia is contained in a rigid sealed tank unknown quality at 0°C. When heated in boiling water to 100°C its pressure reaches 1200 kPa. Find the initial quality, the heat transfer to the ammonia and the total entropy generation.

Answer 1

C.V. Ammonia, which is a control mass of constant volume.

Energy Eq. u₂ - u₁ = ₁q₂ - ₁w₂ 

Entropy Eq  s₂ – s₁ = ∫ dq/T + 1s² _gen 

State 2: 1200 kPa, 100°C