For the study of heat exchange to be performed more accurately, it is performed within a device called calorimeter, which consists of a closed container unable to exchange heat with the environment and its interior.
Within a calorimeter, the placed bodies exchange heat until they reach thermal equilibrium. Since bodies do not exchange heat with the calorimeter or the environment, all thermal energy passes from one body to the other.
Like, when absorbing heat Q> 0 and transmitting heat Q <0, the sum of all thermal energies is zero, ie:
ΣQ = 0
(it reads that the sum of all heat amounts is zero)
Heat amounts can be both sensitive and latent.
What is the equilibrium temperature between a 200g aluminum block at 20 ° C dipped in one liter of water at 80 ° C? Specific heat data: water = 1cal / g ° C and aluminum = 0.219cal / g ° C.
Note that in this example we consider the mass of water to be 1000g, as we have 1 liter of water.