Initially an insulated rigid tank contains 1968 kg of water

Initially, an insulated rigid tank contains 19.68 kg of water at 21.18 Celsius and 101 kPa. The tank also contains a 3.74 kg copper block at 92.12oC. Assume constant specific heats where Cwater = 4.179 kJ/kg-K and CCu = 0.385 kJ/kg-K. Determine the final equilibrium temperature (K).

Correct Answer:

Solution

Heat loss by copper block = heat gained by water

mass_Cu * Cp * ( 92.12 - Tf )   = mass_water * Cp_water * ( Tf - 21.18 )

3.74 * 0.385 * ( 92.12 - Tf ) = 19.68 * 4.179 * (Tf - 21.18 )

( 92.12 - Tf )   = 57.116966 * (Tf - 21.18 )

Tf = 22.4 C or 295.55 K