40 g of water at 600C is poured into a vessel containing 50 g of water at 200C. The final temperature recorded is 300C. Calculate the thermal capacity of the vessel. (Take specific heat capacity of water as 4.2 Jg−10C−1).
2942 J 0C-1
Let the thermal capacity of the vessel be C’.
According to the principle of mixture,
Heat given by hot water = Heat taken by cold water and vessel
40×4.2Jg−1 0C−1×(60−30)0C=50g×4.2Jg−1 0C−1×(30−20)0C+C′×(30−20)0C
C′=2942 J 0C−1