Question

In an experiment, 698 g of water is in a copper calorimeter cup of mass 204 g. The cup and the water are at an initial temperature of 11.3 ^oC. An unknown material with a mass of 411 g at a temperature of 421.8 ^oC is placed in the water. The system reaches thermal equilibrium at 31.1 ^oC. What is the specific heat of the unknown material?

Answer 1

we have the specific heat capacity of water,

also,the specific heat capcity of copper,

Here mass of water,

mass of copper calorimeter cup,

initial temperature of water and copper calorimeter cup,

mass of unknown matierial added to the calorimetric system,

temperature of unknown mass,

final temperature of the system,

let the specific heat capacity of unknown matierial be,

from the law of conservation of heat of calorimetric principle,

net heat lost by one body=net heat gained by the other body.

Here the temperature of copper calorimeter and water increases indicates it had gained the heat,and the temperature of unknown substance decreases indicates that it losses the heat.

so,total heat gained by water and copper calorimeter=total heat lost by unknown substance

heat gained by water=

heat gained by copper calorimeter=

so total heat gained by water+heat gained by the calorimeter=

=698*4.2*(31.1-11.3) + 204*0.385*(31.1-11.3)=59600.772J

heat lost by unknown substance=

=

since,heat absorbed by water and copper calorimeter=heat lost by unknouwn substance

implies,

so specfic heat capacity of unknown substance is,