PHYS 2001 Lecture Notes - Lecture 28: Heat Capacity, The Technique, Italian National Olympic Committee
12.7 (cont.) Calorimetry
Calorimetry is a technique that one can use to determine the specific heat of an
unknown substance.
The technique is based on the conservation of energy.
The unknown material with a mass m
o
and
o
temperature T
ois placed into a calorimeter.
The heat (internal energy) lost by the unknown
material must go into heating up the water and the
calorimeter cup.
The calorimeter cup is well insulated to reduce the
heat lost to the environment.
Hlb k ilH idb
H
eat
l
ost
b
y un
k
nown mater
i
a
l
=
H
eat ga
i
ne
d
b
y
container + Heat gained by the water
w
c
o
Q
Q
Q
Δ
+
Δ
=
Δ
w
c
o
Q
Q
Q
Heat lost by
unknown
material
Heat gained
by container
Heat gained
by water
wwwcccooo
T
mc
T
mc
T
mc
Δ
+
Δ
=
Δ
From this equation, we can determine co, the heat capacity of the unknown sample.
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Document Summary
Calorimetry is a technique that one can use to determine the specific heat of an unknown substance. The technique is based on the conservation of energy. The unknown material with a mass m temperature t: and, is placed into a calorimeter. o. The heat (internal energy) lost by the unknown material must go into heating up the water and the calorimeter cup. The calorimeter cup is well insulated to reduce the heat lost to the environment. l b. Heat lost by unknown material = heat gained by container + heat gained by the water i l h i d b k. From this equation, we can determine c o, the heat capacity of the unknown sample. Example: a precious-stone dealer wishes to find the specific heat capacity of a 0. 030-kg gemstone. When thermal equilibrium is established, the temperature is 28. 5 oc. Heat lost by the gemstone = heat gained by the vessel + heat gained by the water.
