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Problems related to entropy change

A) Two compartments each of 1 m3 capacity are joined by a valve and insulated from the surroundings and from one another. One compartment has saturated steam at 683.6 kPa and the other contains steam at the same temperature but at a pressure of 101.3 kPa. The valve is opened and the pressure is allowed to equalize. Evaluate the change in entropy of the system consisting of the two vessels.  Is this procedure irreversible?
 
B) A house is air conditioned using solar energy. The Solar radiation heats a pressurized tank such that the temperature is maintained at 175oC.  1500 kJ must be extracted from the house to maintain the temperature at 24oC when the ambient temperature is 33oC. Determine the minimum quantity of heat that must be extracted from the tank of water by any device built to accomplish the required cooling of the house. 
 
C) A 2kg piece of copper at 200oC is taken out of a furnace and is permitted to cool in air with an ambient temperature of 25oC. Calculate the entropy change in the universe as a result of this process. The Cp of copper is 0.38 kJ/kg K.

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