Hypothesis

If the change in temperature is greater when the water is heated with the use of the fire caught by the food substance, then the energy content in the food substance is higher because the heat energy is greater, since the heat energy is absorbed by the water when the fire is kept under the test tube containing water. The formula indicates that if the change in temperature is greater when the mass of the substances and the volume of water are constant, then the heat energy is higher.

The conclusion drawn by my hypothesis is:

equation-1-1

Apparatus

  • Test Tube
  • Measuring Cylinder
  • Laboratory Thermometer
  • Water
  • Needle with Handle
  • Scalpel (for cutting the substances into exactly 0.5 grams)
  • Test tube holder
  • Burner
  • The following substances are the 5 different food items that are used to conduct the experiment, the substances used are:

i.      Biscuit

ii.      Koko  Crunch

iii.      Cheetos

iv.      Peanut

v.      Candlenut

Variables

  • Independent Variable: Heat energy of the food substance used.
  • Dependent Variable: Temperature change in the water/Amount of energy absorbed.
  • Controlled Variable: Amount of water, Temperature of surroundings, Type of needle used, Temperature of water.

Manipulation

  • Independent Variable: As we vary the food items that we use, their heat energy/ they themselves become the independent variable.
  • Dependent Variable: The change in temperature/ Heat energy absorbed is varied as the heat energy of the substance is varied.
  • Controlled Variable: The temperature is not varied in any case or does not depend on anything during this experiment, amount of water equals 20ml in each trial of experiment for each food substance.

Procedure

  • Measure 20ml water in the measuring cylinder and pour in the test tube.
  • Place the test tube in the holder and lock it tight.
  • If the food substance measures 0.5 grams on the electrical balance, then use the substance, otherwise use the scalpel to divide it into smaller pieces and make sure it measures exactly 0.5 grams.
  • Measure the initial temperature of water using the thermometer
  • Poke through a food substance measuring 0.5 grams using the needle with the handle.
  • Turn on fire on the burner.
  • Set the food substance on the needle to fire on the burner.
  • Once the food substance starts to burn, place it under the test tube so the water inside it can absorb heat.
  • Measure the temperature change in the water using the thermometer.
  • Measure the energy content in the food item by using the following formula:

equation-1-2

Set up

lab-setup-1

lab-setup-2

Results

BiscuitInitial Temp (ᵒC) of WaterAfter Burn Temp(ᵒC) WaterMass (g)

Biscuit

Energy Content of Biscuit (kJ)
Trial 126350.531.426
Trial 227410.512.305
Trial 327490.513.696
Koko KrunchInitial Temperature of Water (ᵒC)After Burn Temperature (ᵒC) WaterMass (g) of the Koko CrunchEnergy Content (kJ)
Trial 12533.50.51.428
Trial 225300.50.840
Trial 325330.51.344
CheetosInitial Temperature of Water (ᵒC)After Burn Temperature of Water (ᵒC)Mass (g) of the CheetosEnergy Content of Cheetos (kJ)
Trial 126440.53.024
Trial 225490.54.032
Trial 325450.53.360
CandlenutInitial Temperature of Water (ᵒC)After Burn Temperature of Water (ᵒC)Mass (g) of the CandlenutEnergy Content of Candlenut (kJ)
Trial 125760.58.568
Trial 228790.58.568
Trial 328800.58.736
PeanutInitial Temperature of Water (ᵒC)After Burn Temperature of Water (ᵒC)Mass (g) of the PeanutEnergy Content of the Peanut (kJ)
Trial 128640.496.171
Trial 225600.55.880
Trial 327.5520.54.116

lab-graphs-1-2

Average Results

Food ItemEnergy T1(kJ)Energy T2(kJ)Energy T3(kJ)Average Energy (kJ)
Biscuit1.4262.3053.6962.476
Cheetos3.0244.0323.3603.472
Koko Crunch1.4280.8401.3441.204
Candlenut8.5688.5688.7368.652
Peanut6.1715.8804.1165.839

food-substance-energy-graph

Discussion of Results

The least energy as the graph shows is in the Cereal (Koko Crunch). It contains about 1.2 kJ of Average Energy. Candlenut contains the highest amount of energy in the 5 items used during the experiment possessing energy of approximately 8.6kJ.

The trials of the Biscuit show increasing energy from T1 to T3, causing the Average Energy to be higher than the energy obtained in T1 and T2 but lesser than T3. The results of Candlenut show a similar pattern and Peanuts have an opposite pattern.

The results of Cheetos show a pattern of results being T1 (Least) – T2 (Highest) – T3 (Lesser than Highest and Higher than Least). The Average Energy in this case is just a bit higher than the T3. The Koko Crunch shows the opposite pattern and therefore the Average Energy observed is higher than T3.

The trials of Biscuit and Peanut show high variation, this shows the inaccuracy in the results that can be explained by evaluating the method used.

Conclusion

My results completely agree with my hypothesis that when the temperature change is greater, the energy content is higher.  My hypothesis states:

If the change in temperature is greater when the water is heated with the use of the fire caught by the food substance, then the energy content in the food substance is higher because the heat energy is greater, since the heat energy is absorbed by the water when the fire is kept under the test tube containing water. The formula indicates that if the change in temperature is greater when the mass of the substances and the volume of water are constant, then the heat energy is higher.

If compared to my results, I can vouchsafe that my hypothesis agrees with my results.

Evaluation

The experiment was done with the best method possible in the lab with the provided equipment. The accuracy could be increased by:

  • Use a calorimeter to insulate the test tube to prevent loss of heat energy.
  • Use a digital thermometer for accurate readings of temperature.
  • Prevent the carbon coating that is formed on the test tube when a substance is burnt as it forms insulation.
  • Try to have a handle made out of wood for the needle as a metal conducts heat.
  • Conduct more trials.
  • Turn of the A/C and perform the experiment at room temperature.
  • Use exactly 0.5 grams of food substances. Prevent even the minute errors.

Leave a Reply

4 Comments on "Lab Answers: Energy from Burning Food"

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Zahin
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Thanks a lot!! I really appreciate it!!!! It helped me with my homework and to be frank, it fulfilled my requirements!! Please keep it up!! 😉

Richard
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What formula do you use to calculate the amount of Joules?

Selena T.
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Really great .. thank you so much

Shamar
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Thanks a lot this helped me with my plan and design lab.Thanks much really appreciate it 😊😊

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