A 0.50 kg block of iron [c = 0.44 kJ/(kg·K)] at 20.0°C is in contact with a 0.50 kg block of aluminum [c = 0.900 kJ/(kg·K)] at a temperature of 20.0°C. The system is completely isolated from the rest of the universe. Suppose heat flows from the iron into the aluminum until the temperature of the aluminum is 22.0°C. 

(a) From the first law, calculate the final temperature of the iron. 

(b) Estimate the entropy change of the system. 

(c) Explain how the result of part(b) shows that this process is impossible.