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5. Additionally required equipment
5.1 For measuring temperature
1 Digital Thermometer, 1 Channel
and
1 K-Type NiCr-Ni Immersion Sensor 1002804
or
1 Tube thermometer
5.2 For determining specific heat capacity of
solids
Aluminium shot, 100 g
Copper shot, 200 g
Glass shot, 100 g
5.3 To power the heater
1 DC power supply 20 V, 5 A (@230 V) 1003312
or
1 DC power supply 20 V, 5 A (@115 V) 1003311
5.4 To measure time
1 Mech. stopwatch, 15 min
6. Sample experiments
6.1 Specific heat capacity of solids
•
Find the mass m
1
ium beaker and make a note of it.
•
Half fill the beaker with water and weigh it
again, making a note of the mass of the wa-
ter m
.
2
•
Insert the beaker into the calorimeter and
put on the lid without adding the heating coil
to it.
•
Slot an immersion sensor or a thermometer
into the opening in the calorimeter, making
sure that the tip of the instrument does not
touch the bottom of the vessel.
Make a note of the initial temperature ϑ
•
•
Determine the mass m of the solid body and
make a note of it.
•
Heat the solid body in boiling water and
make a note of the new temperature ϑ
•
Quickly transfer the solid body into the calo-
rimeter and close the lid.
•
Move the stirrer up and down and then
measure the temperature of the mixture ϑ .
•
Calculate the specific heat capacity c of the
solid body using the following equation:
(
) (
ϑ
−
ϑ
⋅
⋅
m
1
1
=
c
(
⋅
ϑ
m
2
3B Scientific GmbH ▪ Rudorffweg 8 ▪ 21031 Hamburg ▪ Germany ▪
1002793
1003526
1000832
1000833
1000834
1003369
of the innermost alumin-
1
2.
)
+
⋅
c
m
c
1
2
2
)
−
ϑ
Technical amendments are possible
© Copyright 2012 3B Scientific GmbH
= specific heat capacity of water
c
1
=
, 4
182
c
1
kg
= specific heat capacity of aluminium
c
2
=
, 0
896
c
2
kg
6.2 Determining electrical equivalent of heat
•
Slot an immersion sensor or a thermometer
into the opening in the calorimeter. The tip of
the instrument should be below the heating
filament but must not touch the bottom of the
vessel.
Make a note of the initial temperature ϑ
•
•
Connect up the power supply.
•
Turn on the power supply and start measur-
ing the temperature from that instant. Do not
exceed a voltage of 6 V or a current of 2 A.
Read off the values from the power supply
itself and make a note of them.
•
Heat the water for a maximum of 15 min-
utes. To make sure the heating is uniform,
slowly move the stirrer up and down while
the power is switched on.
•
Turn off the power supply and halt the stop-
watch at the same instant. Make a note of
the time t.
Measure the final temperature ϑ
•
a note of it.
The electricity W that has been converted into
heat is given by the following equation:
=
⋅
⋅
W
I
U
t
The quantity of heat absorbed Q can be calcu-
lated using the following equation:
(
=
⋅
Q
m
c
1
1
= specific heat capacity of water
c
1
=
, 4
182
c
1
.
kg
= specific heat capacity of aluminium
c
2
=
, 0
896
c
2
kg
An approximate value for the electrical equiva-
lent of heat is given by the following equation:
Q
q =
.
W
•
Compare the amounts of electrical and
thermal energy involved in the experiment.
kJ
⋅
K
kJ
⋅
K
) (
)
+
⋅
⋅
ϑ
−
ϑ
m
c
2
2
2
1
kJ
⋅
K
kJ
⋅
K
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.
1
and make
2
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