酢酸ナトリウムの発熱結晶化

瞬間結晶化で放出される熱を測定する

Thermochemistry Intermediate (High School) 30 分 ~$8.00

目的

熱量測定法を用いて過飽和酢酸ナトリウムの結晶化で放出される熱を定量する。

背景

When supersaturated sodium acetate crystallizes, it releases stored energy as heat. By triggering crystallization inside a calorimeter and measuring the temperature rise, the enthalpy of crystallization can be determined. This is the same principle used in reusable hand warmers.

安全上の警告

  • Hot solution during preparation
  • Crystallization releases heat — container gets warm

必要なPPE

goggles

材料

  • Sodium acetate trihydrate (80 g)
  • Distilled water (150 mL)

器具

Polystyrene cup calorimeter Hot plate Thermometer Beaker (250 mL) Stirring rod

手順

1

Dissolve 80 g sodium acetate trihydrate in 20 mL water by heating to about 70°C. Stir until clear.

8 分 Handle hot solution carefully
2

Pour the solution into the polystyrene cup calorimeter. Allow to cool undisturbed to room temperature.

15 分
3

Record the temperature of the supersaturated solution.

1 分
4

Add a single small crystal of sodium acetate to trigger crystallization. Immediately stir gently and record temperature every 15 seconds.

3 分
5

Record the maximum temperature reached.

1 分
6

Calculate the heat released: q = mcΔT. Determine ΔH of crystallization per mole.

5 分

予想される結果

Temperature should rise 15-25°C above room temperature. The enthalpy of crystallization is approximately -19.7 kJ/mol for sodium acetate trihydrate. Measured values should be within 20% of this.

後片付け

The sodium acetate can be remelted and reused. Rinse the calorimeter. Non-toxic — can go down the drain.

詳細

カテゴリ
Thermochemistry
難易度
Intermediate (High School)
所要時間
30 分
推定費用
$8.00
ステップ数
6
材料
2

その他の実験

コーヒーカップ熱量測定 40 min コールドパックの化学 20 min ヘスの法則の検証 60 min マグネシウムの燃焼熱 50 min 吸熱反応のデモンストレーション 20 min 氷の融解エンタルピー 25 min 溶解は常に発熱ではない 25 min 爆弾熱量測定シミュレーション 45 min 金属の比熱容量 40 min

Frequently Asked Questions

What is the objective of 酢酸ナトリウムの発熱結晶化?
熱量測定法を用いて過飽和酢酸ナトリウムの結晶化で放出される熱を定量する。
How difficult is 酢酸ナトリウムの発熱結晶化?
This experiment is rated as Intermediate (High School). It takes approximately 30 minutes to complete.
What safety precautions are needed for 酢酸ナトリウムの発熱結晶化?
Key safety precautions include: Hot solution during preparation; Crystallization releases heat — container gets warm.
What materials are needed for 酢酸ナトリウムの発熱結晶化?
The main materials required are: Sodium acetate trihydrate, Distilled water.
What results should I expect from 酢酸ナトリウムの発熱結晶化?
Temperature should rise 15-25°C above room temperature. The enthalpy of crystallization is approximately -19.7 kJ/mol for sodium acetate trihydrate. Measured values should be within 20% of this.