1. Chemistry 1011 TOPIC TEXT REFERENCE Thermochemistry
Masterton and Hurley Chapter 8
Chemistry 1011 Slot 5

2. 8.2 Measurement of Heat Flow
YOU ARE EXPECTED TO BE ABLE TO:
Identify the components and describe the operation of a bomb calorimeter.
Calculate q for a chemical reaction from calorimetric data.
Chemistry 1011 Slot 5

3. Simple Calorimeter
A calorimeter is an insulated apparatus of known heat capacity
Processes (reactions) can be carried out in a calorimeter in order to measure the heat change that takes place
In an exothermic reaction (the reaction gives out heat) heat flows from the reaction to the calorimeter and the temperature of the calorimeter and contents will rise
qcalorimeter is +ve qreaction is –ve
qreaction = – qcalorimeter
Chemistry 1011 Slot 5

4. Some heat is absorbed by the metal as well as the surrounding water.
Bomb Calorimeter
Some heat is absorbed by
the metal as well as
the surrounding water.
Chemistry 1011 Slot 5

5. Using the Bomb Calorimeter
Place weighed sample in the bomb
Seal and place in calorimeter; add water
Measure initial temperature; Conduct reaction; Measure final temperature
qreaction = – qcalorimeter = – Ccalorimeter x Dt
Chemistry 1011 Slot 5

6. Bomb Calorimeter Calculation
Combustion of 1.60 g CH4 in bomb calorimeter raises the temperature by 5.14C
(The heat capacity of the calorimeter is Ccalorimeter = 17.2 kJ/C)
q reaction = kJ/C  5.14C = kJ
Chemistry 1011 Slot 5