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An unknown metal of mass 192 g heated to a temperature of 100°C was immersed in a brass calorimeter of mass 128 g containing 240 g of water at a temperature of 8.4°C. Calculate the specific heat of the unknown metal if water temperature stabilizes at 21.5°C. (Specific heat of brass is 394 J kg⁻¹ K⁻¹)

1. 458 J kg⁻¹ K⁻¹
2. 1232 J kg⁻¹ K⁻¹
3. 654 J kg⁻¹ K⁻¹
4. 916 J kg⁻¹ K⁻¹

Correct answer: 916 J kg⁻¹ K⁻¹

Solution

The specific heat of the unknown metal is calculated using the principle of conservation of energy, where the heat lost by the metal equals the heat gained by the water and the brass calorimeter. The calculations show that the specific heat of the metal is 916 J kg⁻¹ K⁻¹, which balances the energy transfer in the system.

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