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The heat capacity of the entire calorimeter system (*C*) is the sum of the heat capacities of the calorimeter
(*C _{cal}*) and all of the substances in the calorimeter. Although water is the most frequently used liquid,
it is possible to employ a liquid other than water in the calorimeter. In this example, suppose the calorimeter contains ethanol.
The heat capacity of the entire calorimeter system is thus

*
C = C _{cal} + C_{EtOH}
*

The heat capacity of the ethanol (*C _{EtOH}*) depends upon how much ethanol is in the system. It is therefore more
convenient to replace

*
C = C _{cal} + s_{EtOH} m_{EtOH}
*

Experimentally one knows the mass of ethanol used in the experiment, and one can measure the heat capacity of the entire calorimeter system.
This leaves two unknowns, *C _{cal}* and

One approach to determining these values is to perform two experiments using two different masses of ethanol.
Two equations involving *C _{cal}* and

A superior strategy for determining *C _{cal}* and

**Objectives:**

- Determine the heat capacity of the calorimeter (
C)._{cal}- Determine the specific heat capacity of ethanol (
s)._{EtOH}

**Approach:**

- Use the heating element to transfer a known amount of heat to the calorimeter system.
- Observe the temperature of the system before and after the heating process.
- Calculate the change in temperature for the system.
- Calculate the heat capacity of the entire calorimeter system (
C).- Prepare a plot of
Cvsm._{EtOH}- Obtain
Cand_{cal}sfrom the intercept and slope, respectively, of the line-of-best-fit._{EtOH}

Perform a series of experiments using different masses of ethanol. Prior to each experiment, enter the mass of ethanol
(between 300. and 1000. g). Reset the simulation and then perform the virtual experiment. The heating element is set to transfer a total of
**50 kJ** of heat to the calorimeter.

After each experiment, calculate the heat capacity of the entire calorimeter system (*C*). Enter the values for *C* and
*m _{EtOH}* in the "Add Point" fields and click on the "Add Point" button. This data point will be plotted on the graph.

When you have plotted at least four points, click on the "Draw Line" button, and the line-of-best-fit will be plotted and the slope and intercept displayed.

Bear in mind that random error has been added to the simulated data. One consequence of this error is that the points will not all
lie perfectly on a line. Another consequence is that the values for *C* and *m _{EtOH}* obtained from the linear
regression will not be perfectly accurate. Try repeating measurements to see the reproducibility of the data.

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