Question 4: [15] You have two identical pieces of copper, each weighing 200 g, in contact with each other, the temperature of the one being 900°C, that of the other 75°C. Heat transfer should only be between the two metal pieces, but not with the surroundings. 4.1 What will happen to the temperature of the copper pieces? (5) 4.2 Is what is happening reversible or irreversible (spontaneous)? (5) 4.3 Calculate the change of entropy that occurs (use mean heat capacity value for copper) (5) 3 21°C A 15 3​