A metal of mass 0.5kg is heated to 100°C and then transferred to a well-lagged calorimeter of heat capacity 80JK-1 containing water of heat capacity 420JK-1 at 15°C. If the final steady temperature of the mixture is 25°C, find the specific heat capacity of the metal.
-
A.
877Jkg-1K-1 -
B.
286Jkg-1K-1 -
C.
133Jkg-1K-1 -
D.
92Jkg-1K-1
Correct Answer: Option C
Explanation
Let the specific heat cap. of the metal = C
∴ Heat lost by the metal = heat gained by the Calorimeter + Water
∴ 0.5 x C x [100 – 25]
80 x [25 – 15] + 420 [25 – 15]
0.5 x C x 75 = 80 x 10 + 420 x 10
37.5C = 800 + 4200
C = 5000/37.5 = 133.3Jkg-1K-1