Question 20
Quantity of HeatA metal of mass 0.5 kg is heated to 100 °C and then transferred to a well-lagged calorimeter of heat capacity 80 J K−1 containing water of heat capacity 420 J K−1 at 15 °C. If the final steady temperature of the mixture is 25 °C, find the specific heat capacity of the metal.
- A.92 J kg−1 K−1
- B.133 J kg−1 K−1
- C.286 J kg−1 K−1
- D.877 J kg−1 K−1
Show the answer and explanation
Answer: B (133 J kg−1 K−1)
Explanation
Heat lost by metal = heat gained by calorimeter and water: 0.5 × c × 75 = (80 + 420) × 10 = 5000. So c = 5000/37.5 ≈ 133 J kg−1 K−1.