Unit 2: Keeping up standards
B: Practical scientific procedures and techniques
Keeping up the standards
Calorimetry is a form of science investigation which requires
using a calorimeter to measure changes of state, phase and
chemical reactions in terms of the associated heat transferred.
A calorimeter is a container which can be used with a
thermometer, for example, a glass or beaker or polystyrene cup.
The thermometer measures the temperature during a reaction in
which heat is exchanged with the immediate outer environment.
A few examples of general uses include, monitoring
endothermic/exothermic reactions, monitoring change of
physical phase, e.g. in freezing, liquid becomes a solid, and
melting, where a solid becomes a liquid. This is also used in
measuring specific heat capacity.
In the investigation, the two materials used are paraffin wax and
stearic acid.
Paraffin wax is a flammable, soft colourless solid derived from
petroleum, coal, or shale oil. It consists of a mixture of
hydrocarbon molecules containing between 20 and 40 carbon
atoms. Paraffin wax has a melting point of 37 degrees Celsius
and a boiling point of greater than 370 degrees Celsius and its
chemical formula is CnH2N+2.
Stearic acid is a saturated fatty acid which has an 18-carbon
chain. It is a waxy solid with a melting point of 69.3 degrees
Celsius and a boiling point of 361 degrees Celsius and its