Bombenkalorimetrie-Simulation

Messung des Energiegehalts von Lebensmitteln durch Kalorimetrie

Thermochemistry Intermediate (High School) 45 Min. ~$10,00

Ziel

Den Energiegehalt (Kaloriengehalt) verschiedener Lebensmittel messen, indem sie verbrannt und die auf Wasser übertragene Wärme gemessen wird.

Hintergrund

A simple food calorimeter uses the heat from burning food to raise the temperature of water. By measuring the mass of food burned and the temperature rise of the water, the energy content can be calculated. This demonstrates why some foods have more calories than others.

Sicherheitswarnungen

  • Open flame — keep flammables away
  • Burning food produces smoke — ventilate
  • The can will get hot — do not touch with bare hands

Erforderliche PSA

goggles lab_coat

Materialien

  • Food samples (10 g each)
    Peanuts, cashews, marshmallows, chips
  • Distilled water (400 mL)
  • Aluminum foil (1 sheet)
    For makeshift shield

Ausrüstung

Empty aluminum soda can Ring stand and ring Needle or pin (mounted) Lighter Thermometer Analytical balance (0.01 g)

Durchführung

1

Measure 100 mL of water and pour into the soda can. Record the initial temperature.

3 Min.
2

Set up the can on the ring stand. Position a mounted needle below the can to hold the food sample.

5 Min.
3

Weigh a food sample (e.g., one peanut) accurately. Impale it on the needle.

2 Min.
4

Light the food sample with the lighter. Position it under the can to heat the water.

5 Min. Open flame — be careful
5

When the food stops burning, immediately stir and record the maximum water temperature.

2 Min. Can is hot
6

Calculate energy: q = m(water) × c × ΔT. Convert to kJ/g or Cal/g.

5 Min.
7

Repeat for different food types. Compare measured values with nutritional labels.

15 Min.
8

Discuss why measured values are lower than label values (heat lost to surroundings).

5 Min.

Erwartete Ergebnisse

Nuts (high fat) should give the highest energy per gram (~25 kJ/g measured vs ~25 kJ/g label). Marshmallows (sugar) ~15 kJ/g. Measured values will be 30-50% lower than label values due to heat losses.

Aufräumen

Allow everything to cool. Dispose of food residue. Rinse the can and clean the work area.

Details

Kategorie
Thermochemistry
Schwierigkeit
Intermediate (High School)
Dauer
45 Min.
Geschätzte Kosten
$10,00
Schritte
8
Materialien
3

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Frequently Asked Questions

What is the objective of Bombenkalorimetrie-Simulation?
Den Energiegehalt (Kaloriengehalt) verschiedener Lebensmittel messen, indem sie verbrannt und die auf Wasser übertragene Wärme gemessen wird.
How difficult is Bombenkalorimetrie-Simulation?
This experiment is rated as Intermediate (High School). It takes approximately 45 minutes to complete.
What safety precautions are needed for Bombenkalorimetrie-Simulation?
Key safety precautions include: Open flame — keep flammables away; Burning food produces smoke — ventilate; The can will get hot — do not touch with bare hands.
What materials are needed for Bombenkalorimetrie-Simulation?
The main materials required are: Food samples, Distilled water, Aluminum foil.
What results should I expect from Bombenkalorimetrie-Simulation?
Nuts (high fat) should give the highest energy per gram (~25 kJ/g measured vs ~25 kJ/g label). Marshmallows (sugar) ~15 kJ/g. Measured values will be 30-50% lower than label values due to heat losses.