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Calorimeters are used to measure potential energy. A calorie is the energy it takes to heat 1 mL of water 1 degree Celsius. These calories are not the same as those used to refer to food on nutrition labels, dietary plans, etc., which are known as Calories or Kcal (1000 normal calories). With some simple, everyday materials, you can construct a homemade calorimeter to determine either the calories or Kcal of a sample of food.

Part 1
Part 1 of 3:

Building the Calorimeter

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  1. [1] This can will be used to contain water that will be heated as part of the calorimetric measurements. Any small metal can will work, such as those used to package vegetables, or a soda can. [2] Make sure that it is empty, clean, and open on one end. If you are using a soda can, the opening used for drinking out of the can will suffice.
  2. [3] You will need a second metal can, large enough that the small metal can will fit inside it with room to spare. Any larger metal can will work, such as a coffee can. Make sure that it is empty, clean, and open on both ends.
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  3. [4] Using a hole punch, ice pick, or other implement, carefully puncture four small holes (each one directly across from another) in the small metal can. Position the holes just below the rim of the open end of the can.
  4. Slide one rod through the can to the other side, then repeat with the other rod and the two remaining holes; the two rods should cross each other. These rods will be used to support the small can in the calorimeter. Temperature-resistant glass rods are ideal. If you do not have any, try any kind of sturdy, nonflammable rod.
  5. Using a graduated cylinder, flask, or other container, pour 100 mL of distilled water in the small metal can.
  6. Using a mercury thermometer (not a digital one), take the initial temperature of your water. You may need to leave the thermometer in the water for some time so that it can get an accurate reading of the water (which may change temperature as it adjusts to room temperature).
    • Leave the thermometer in the water; you will need it to take another reading later.
  7. The small metal can should rest securely inside the larger one, supported by the rods made of glass or another nonflammable material.
  8. A standard-size paperclip will be used to hold the food inside the calorimeter. Completely unfold the paperclip so that it forms a single long strand. Insert one end of the strand into the cork. Make sure it can stand upright with the unfolded paperclip sticking up.
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Part 2
Part 2 of 3:

Using the Calorimeter

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  1. [5] Weigh the food using an accurate scale, and record the measurement. You will only need a small amount of the food. Good choices include a shelled peanut, potato chip, or other high-fat food.
  2. [6] Carefully wrap the end of the paperclip that is not sticking in the cork around the food you will test (or pierce it with the paperclip).
  3. [7] Set the cork on a flat, nonflammable surface so that the food on the paperclip is sticking up. Light the food, using a butane lighter or other device. As soon as it catches fire, place the cans over it.
    • Be very careful lighting the food and placing the cans over it so that you don’t burn yourself.
  4. [8] Keep the cans over the food for as long as it takes to burn completely. As the food burns, it will heat the water in the small can that is suspending in the large can.
    • Carefully watch the food as it burns. If it goes out quickly, before the food burns completely, relight it.
  5. Once the food has completely burned out, stir the water in the small can using the thermometer. Record the temperature of the heated water.
    • Be careful moving or touching the calorimeter, as the cans and other parts may be very hot.
  6. Once the burnt food has cooled completely, remove it from the paperclip. Weigh it again, and record the measurement.
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Part 3
Part 3 of 3:

Calculating

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  1. [9] The formula used to determine the caloric value of a sample of food using a homemade calorimeter is relatively simple: calories = volume of water (in mL) x the temperature change (in Celsius) of the water.
  2. If you filled the small can with exactly 100 mL of distilled water, then you already know the volume of water (100 mL). [10] If you recorded the initial temperature of the water, and its temperature after the food was burned, you can determine the temperature change by subtracting the smaller value from the larger.
    • For instance, if the water in the can was initially 35 degrees Celsius, then 39 degrees Celsius after the food was burned, then you have a temperature change of 4 degrees (39-35 = 4).
  3. Using the formula and the data you collected, determine how many calories were in the food you analyzed. [11]
    • For instance, if you had a temperature change of 4 degrees, then the food contained 400 calories (400 = 100 mL x 4, using the formula calories = volume of water x the temperature change of the water)
    • To determine Kcal of the food, multiply the temperature change of the water by the volume of water in liters. [12] Using the example above, the sample would contain 0.4 Kcal (0.4 Kcal = 0.100 L water x 4)
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Community Q&A

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  • Question
    Why do I need to weigh the food?
    Community Answer
    So that you can get the accurate number of calories per gram of food. You do this by dividing the total calories by the weight of the food.
  • Question
    Will this work for a science Olympiad composition?
    Community Answer
    Yes, you just need to change the mercury thermometer to a digital thermometer.
  • Question
    What do you mean by putting the cans over the burning food?
    Community Answer
    Since the larger can has to be open at both sides (like a tube), and the smaller can is suspended inside, you have to place the can such that the larger can will shroud the burning food, and the small can be directly above the burning food.
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      Things You'll Need

      • Metal cans
      • Food sample
      • Scale
      • Cork
      • Paper clip
      • Graduated cylinder, flask, or other container to measure water
      • Thermometer
      • Implement to punch holes in can

      About This Article

      Article Summary X

      To build a calorimeter, start by puncturing 4 holes in pairs opposite one another just below the rim of an empty soda can. Then, slide 2 thin rods through the pairs of holes so they cross each other. Next, put 100 mL of distilled water in the can, and use a thermometer to check the water’s temperature. After that, put the can inside a larger metal can that’s empty and open on both ends, so the smaller can is suspended by its rods. Finally, insert 1 end of an unfolded paperclip into a cork to serve as a handle for the food going into the calorimeter. To learn how to use your calorimeter, keep reading!

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      • Julia DeChaves

        Feb 26, 2017

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