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Material properties
Dewar flask calorimeter
Ref :
253 081
ENGLISH
Decrease in temperature over
90
85
80
75
70
65
60
55
50
0
5
Between 85 and 72 ° C, the decrease in temperature i s 1.8 ° C per minute, on
.
an average
Below 70° C, the decrease remains almost constant at 0.27 ° C per minute over
the entire measuring range.
The loss of heat therefore remains low considering the experimental
parameters:
•
We are located more than 20 ° C above the ambient t emperature
•
The volume of water represents only 1/5
volume.
4 Experiments
4.1 Heat capacity of the calorimeter
We pour 250 ml of water (cold) at 20.7° C in the cal orimeter
We then pour 250 ml of hot water at 55.2° C in the c alorimeter. The final
temperature is 37.7°C.
According to the following formula,
it is possible to determine the heat
capacity of the calorimeter knowing
that Cwater = 4187 J/Kg/° C.
We show that the heat capacity of the calorimeter with the plastic protective
jacket is 32.05 J/° C.
8
50 minutes
10 15 20 25 30 35 40 45
Time (minutes)
th
of the calorimeter's effective
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