Q&A for How to Build a Calorimeter

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.

Yes, you just need to change the mercury thermometer to a digital thermometer.

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.

Because of the relatively high temperatures associated with candy-making, those thermometers are generally graduated to give the greatest sensitivity to those higher temperature ranges. Calorimeter tests generally involve temperature changes within 10 degrees of room temperature, so a candy-thermometer simply wont work, their scales generally begin at 100 degrees Fahrenheit, and would not even register the reaction.

If it is dried, then remove a small portion, record the fractional weight, and once you find the calories in that small portion, multiply that by the reciprocal of the fraction. Now you have the calories for the large food. (However, this method only works for combustible food.)

As long as you can adjust your calculations to accommodate the difference, the food will still be properly measured.

You can use either thermometer, though mercury is preferred.

Yes, however, you can make sure the thermometer is measuring the water as it heats up-- this way you'll have more accurate results.