Identify the necessary parts to build a calorimeter.
Select one or more:
Thermometer
An exterior styrofoam cup
Conductivity probe
An interior paper cup
An exterior paper cup
Cover
An interior styrofoam cup
The Correct Answer and Explanation is:
Correct Answer
A calorimeter is a device used to measure the amount of heat transferred during chemical reactions or physical changes. A simple calorimeter—often used in school laboratories—can be constructed with relatively inexpensive and accessible materials. The key objective in building a calorimeter is to minimize heat loss to the environment to ensure accurate measurements.
The thermometer is essential because it measures the change in temperature of the system, which is directly related to the heat transfer. Without accurate temperature readings before and after the reaction, calculating the heat released or absorbed would be impossible.
The exterior styrofoam cup provides insulation. Styrofoam is a poor conductor of heat, which makes it ideal for preventing the loss of thermal energy to the surrounding environment. This ensures that most of the heat from the reaction stays within the system, increasing the accuracy of the measurement.
The interior styrofoam cup acts as the container where the actual reaction takes place. Using a second cup inside the first enhances insulation by creating an air gap, which further reduces heat loss. Double-cup construction is a common practice in building effective calorimeters for basic experiments.
A cover is also crucial. It reduces heat exchange between the system and the surroundings by limiting the exposure of the contents to air. The cover often has a hole or slot to allow the thermometer to pass through while still minimizing heat escape.
Incorrect choices:
- An interior paper cup and exterior paper cup are not ideal because paper does not insulate well and allows more heat transfer.
- A conductivity probe measures electrical conductivity, not heat or temperature, and is therefore unnecessary for a calorimeter.
In conclusion, to build an effective calorimeter, one must include a thermometer, a styrofoam cup (preferably double-layered), and a cover to minimize heat loss and ensure accurate readings.
