1. ME 4611: Experiment 5 Bomb Calorimeter Experiment
Yvette Triay - Leader
Group 4

2. Purpose of the Experiment
To understand what a bomb calorimeter is, how to use it, and why it is useful
To determine the thermal capacitance of the calorimeter
To determine the gross heat of combustion of the samples provided

3. What is a bomb-calorimeter?
Used to measure heat created by a sample burned under an oxygen atmosphere in a closed vessel, which is surrounded by water
Temperature differences in water are measured
Thermal capacitance and heat of combustions can be calculated with this data

4. Equipment: Parr Oxygen Bomb Calorimeter
Picture taken from Parr Operating Manual: 1341 Oxygen Bomb Calorimeter [4]

5. Picture taken from Parr Operating Manual: 1341 Oxygen Bomb Calorimeter [4]

6. Thermodynamic Background
1st Law of Thermodynamics
Q=mcvΔT
Q – heat of combustion
mcv – thermal capacitance of the system
ΔT – temperature rise

7. 1) Known Fuel (Benzoic Acid)
2 Tests Conducted
1) Known Fuel (Benzoic Acid)
2) Unknown Fuel
Calorimeter is considered the thermodynamic system
Find thermal capacitance
(mcv)calorimeter=Q/ΔT
Calorimeter capacitance remains constant
Find heat of combustion
Q=(mcv)calorimeterΔT
★ Q is the heat of combustion of the fuel and the ignition wire.

8. Estimate the thermal capacitance of the system (2kg water and 3 kg stainless steel).
(Thermal Capacitance)system = m(H2O)cv(H2O) + m(SS)cv(SS)
(mcv)System = (2 kg)(4180* J/kg-K) + (3 kg)(470* J/kg-K)
(mcv)System = 9770 J/K
* See [1] of Appendices

9. Using Q = 26414* J/g [1], and plugging into the equation
Predict the temperature rise for 1 gram of Benzoic acid, which will be used as the calibration sample.
Using Q = 26414* J/g [1], and plugging into the equation
ΔT = Q/mcv
ΔT = (26414 J/g)*(1 g) / (9770 J/K)
ΔT = 2.7 K
* See [2] of Appendices

10. Appendices [1] Cengal, Yunus
Appendices [1] Cengal, Yunus. Heat and Mass Transfer: Fundamentals & Application, 4th Ed. [2] [3] ME 4611 Laboratory Manual: Experiment 5 – Bomb Calorimeter Experiment [4] Parr Operating Manual: 1341 Oxygen Bomb Calorimeter [5] 1st Law of Thermodynamics: (total energy entering a system ) – (total energy leaving a system) = (change in total energy of the system)