1. How much energy (in J) is required to raise the temperature of 500 g of water from 20 to 100C, and then turn it to steam at 100C?

2. A 2 kg rod of aluminum (c = 0.9 kJ/kg-C) at 90C is dropped into 5 L of water at 4C.  What is the final temperature of the mixture? 

3. A 0.2 kg block of an unknown metal at 50C is immersed in 1L of water at 4C.  The equilibrium temperature of the mixture is 25C.   What is the specific heat of the metal, in kcal/kg-C ?

4. A liter of gas, initially at a pressure of 500Pa, is compressed from 1.00 L to 0.30 L.  During the compression process, heat is dissipated to maintain a constant temperature.  What is the final pressure? 

5. A large thermoelectric array generates electricity by extracting heat from water at the surface of the ocean (25C) and dissipating it into the colder water at the bottom of the ocean (-2C).  What is the maximum ideal efficiency of this arrangement?