Determine a suitable thermodynamic system for measuring the

Determine a suitable thermodynamic system for measuring the chemical energy released by the fuel in the bomb calorimeter. Identify the forms of energy transfer (if any) that would cross the boundary of your thermodynamic system.

Solution

Construction of bomb calorimeter:-

Working:-

The bomb calorimeter comprise of the sample, oxygen, the stainless steel bomb, and water.

The dewar as shown in figure prevents heat flow from the calorimeter to the rest of the universe, i.e.,

q_calorimeter = 0

As the bomb is made from stainless steel (Rigid body), the combustion reaction occurs at constant volume and there is no work, i.e.,

w_calorimeter = p dV = 0

Thus, the change in internal energy, DU, for the calorimeter is zero

DU_calorimeter = q_calorimeter + w_calorimeter = 0

The thermodynamic interpretation of this equation is that the calorimeter is isolated from the rest of the universe. Since the calorimeter is isolated from the rest of the universe, we can define the reactants (sample and oxygen) to be the system and the rest of the calorimeter (bomb and water) to be the surroundings.

Answer:-

Thermodynamic system here is Sample and oxygen, and surrounding is rest of calorimeter (Bomb and water).

Energy in form of ‘Heat energy’ will cross the boundary of our thermodynamic system (Sample and oxygen). That heat crossing system will go into surrounding (Bomb and water). No work will be crossing the boundary of thermodynamic system.