Temperature Change Burning Food

Food sample Mass of Food (g) Starting Water Temperature (C) Final Water Temperature (C)
Saltine Cracker 2 22 23.5
Pecan 2 22 30.5
Dorito chip 2 22 28.0
Peanut 2 22 29.0
Cheeto 2 22 24.5


All foods contain chemical energy, but the amount of chemical energy is dependent of the type of food. The larger the compound, the more chemical bonds, and the greater amount of available chemical energy. We refer to the stored chemical energy in foods as calories. A calorie is the amount of energy required to raise the temperature of 1 gram of water 1 degree Celsius. When we refer to the calories in food, we are really talking about kilocalories or 1000 calories.

Biology students used calorimetry to determine the energy provided by various food samples. They picked food samples of the same mass, 2 grams, and then set the food on fire using kitchen matches. The heat energy of the flaming food was used to heat 100 mL of water. Student results can be seen in the chart above.
What is one condition that may have reduced the accuracy of the temperatures recorded by the student groups?
A) type of foods used in the experiment
B) placement of thermometers in the cans
C) mass of food items used in experiment
D) amount of water measured into the cans