A 0.04-m3 tank initially contains air at ambient conditions of 100 kPa and 22°C. Now, a 15-L tank containing liquid water at 85°C is placed into the tank without causing any air to escape. After some heat transfer from the water to the air and the surroundings, both the air and water are measured to be at 44°C. Determine the amount of heat lost to the surroundings.

One kg of superheated steam is at 400 kPa and 400°C. Heat is added to raise the temperature to 500°C. Find the amount of heat needed (kJ) if: (a) The volume of the steam is kept constant during the heating. (b) The steam is allowed to expand during the heating (e.g., in a piston/cylinder system) such that the pressure is constant. Hint: The steam is not an ideal gas under these conditions.

In a piston cylinder device, by means of a polytropic process, nitrogen is expanded with an n of 1.25, from 2 MPa and 1200 K to 200 kPa. Determine the amount of heat transferred during the expansion process.

A 100L rigid tank contains nitrogen (N2) at 627°C and 6MPA. If the tank is cooled to 100K, the net amount of work and heat involved in this process is kJ