弹式量热计模拟

用量热法测定食物的能量含量

Thermochemistry Intermediate (High School) 45 分钟 ~$10.00

目标

燃烧不同食物并测量传递给水的热量，测定各食物的能量（卡路里）含量。

背景

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.

安全警告

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

所需PPE

goggles lab_coat

材料

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

设备

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

步骤

1

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

3 分钟
2

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

5 分钟
3

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

2 分钟
4

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

5 分钟 Open flame — be careful
5

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

2 分钟 Can is hot
6

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

5 分钟
7

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

15 分钟
8

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

5 分钟

预期结果

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.

清理

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

详情

类别
Thermochemistry
难度
Intermediate (High School)
时长
45 分钟
预估费用
$10.00
步骤数
8
材料
3

更多实验

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Frequently Asked Questions

What is the objective of 弹式量热计模拟?
燃烧不同食物并测量传递给水的热量，测定各食物的能量（卡路里）含量。
How difficult is 弹式量热计模拟?
This experiment is rated as Intermediate (High School). It takes approximately 45 minutes to complete.
What safety precautions are needed for 弹式量热计模拟?
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 弹式量热计模拟?
The main materials required are: Food samples, Distilled water, Aluminum foil.
What results should I expect from 弹式量热计模拟?
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.