محاكاة القياس الحراري بالقنبلة

قياس محتوى الطاقة في الطعام باستخدام القياس الحراري

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

الهدف

قياس محتوى الطاقة (السعرات الحرارية) لمواد غذائية مختلفة عن طريق حرقها وقياس الحرارة المنقولة إلى الماء.

الخلفية

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.

تحذيرات السلامة

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

معدات الوقاية الشخصية المطلوبة

goggles lab_coat

المواد

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

المعدات

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

الإجراء

1

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

3 دقيقة
2

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

5 دقيقة
3

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

2 دقيقة
4

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

5 دقيقة Open flame — be careful
5

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

2 دقيقة Can is hot
6

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

5 دقيقة
7

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

15 دقيقة
8

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

5 دقيقة

النتائج المتوقعة

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.

التنظيف

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

Frequently Asked Questions

What is the objective of محاكاة القياس الحراري بالقنبلة?
قياس محتوى الطاقة (السعرات الحرارية) لمواد غذائية مختلفة عن طريق حرقها وقياس الحرارة المنقولة إلى الماء.
How difficult is محاكاة القياس الحراري بالقنبلة?
This experiment is rated as Intermediate (High School). It takes approximately 45 minutes to complete.
What safety precautions are needed for محاكاة القياس الحراري بالقنبلة?
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 محاكاة القياس الحراري بالقنبلة?
The main materials required are: Food samples, Distilled water, Aluminum foil.
What results should I expect from محاكاة القياس الحراري بالقنبلة?
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.