Two substances initially at different temperatures are brought into contact inside a perfectly insulated coffee-cup calorimeter. No phase changes or chemical reactions occur.
Answer the following qualitative questions about the thermal behavior of the system.
(a) Explain, in terms of energy transfer, why the final equilibrium temperature of the two-substance system must lie between the two initial temperatures.
(b) In separate trials, a 50.0 g sample of Metal X and a 50.0 g sample of Metal Y are each heated to 100.0∘C and then transferred to individual calorimeters that contain 100.0 g of liquid water at 25.0∘C. Metal X has a specific heat capacity of 0.90Jg−1∘C−1, whereas Metal Y has a specific heat capacity of 0.39Jg−1∘C−1. Without performing detailed calculations, predict which trial will produce the higher final water temperature and justify your answer.
(c) A student determines the specific heat capacity of an unknown metal by inserting the hot metal into water contained in a calorimeter but neglects the heat absorbed by the calorimeter itself. State whether this oversight will cause the calculated specific heat capacity of the metal to be too high, too low, or unaffected. Provide a brief explanation based on energy considerations.