砂糖の結晶（ロックキャンディ）

糸に食用の砂糖結晶を育てる

Crystallization Beginner (Middle School) 25 分 ~$4.00

目的

糸の上に大きな砂糖（スクロース）結晶を育ててロックキャンディを作り、食べられる製品で過飽和と核形成を実証する。

背景

Rock candy is made by suspending a string in a supersaturated sugar solution and waiting for crystals to grow. Sugar is unusual in that it is extremely soluble in water (about 2 kg per liter at 100°C) and forms large monoclinic crystals with well-defined facets.

安全上の警告

  • Sugar syrup is extremely hot — burns risk
  • Supervise children during the boiling step

必要なPPE

goggles

材料

  • Granulated sugar (500 g)
    White sugar
  • Water (200 mL)
  • Cotton string (30 cm)
    Unbleached
  • Food coloring (5 drops)
    Optional
  • Flavoring extract (1 tsp)
    Optional

器具

Saucepan Stove or hot plate Tall glass jar Pencil Clothespin

手順

1

Heat 200 mL water to boiling in the saucepan. Gradually dissolve 400-500 g sugar, stirring continuously.

10 分 Hot syrup — burns risk
2

Remove from heat. Add food coloring and flavoring if desired.

2 分
3

Wet the cotton string with water and roll in granulated sugar to create nucleation sites. Let dry for a few hours.

3 分
4

Pour the cooled (but still warm) sugar solution into the glass jar.

2 分
5

Suspend the prepared string from a pencil across the top of the jar so it hangs in the solution without touching the sides or bottom.

3 分
6

Cover loosely and place in a stable location. Check daily for 5-7 days. Crystals should grow along the string.

5 分

予想される結果

After 5-7 days, large sugar crystals (1-3 cm) should form along the string, creating rock candy. Crystals are monoclinic with flat, angled faces. The result is edible.

後片付け

Excess sugar solution can be reheated and reused. Wash all equipment with warm water.

詳細

カテゴリ
Crystallization
難易度
Beginner (Middle School)
所要時間
25 分
推定費用
$4.00
ステップ数
6
材料
5

その他の実験

サロール（サリチル酸フェニル）の結晶化 30 min ビスマス虹色結晶の育成 45 min ミョウバン結晶の育成 30 min 塩と砂の分別結晶化 35 min 安息香酸の再結晶精製 45 min 硫酸銅結晶の育成 30 min 過飽和と瞬間結晶化 35 min

Frequently Asked Questions

What is the objective of 砂糖の結晶（ロックキャンディ）?
糸の上に大きな砂糖（スクロース）結晶を育ててロックキャンディを作り、食べられる製品で過飽和と核形成を実証する。
How difficult is 砂糖の結晶（ロックキャンディ）?
This experiment is rated as Beginner (Middle School). It takes approximately 25 minutes to complete.
What safety precautions are needed for 砂糖の結晶（ロックキャンディ）?
Key safety precautions include: Sugar syrup is extremely hot — burns risk; Supervise children during the boiling step.
What materials are needed for 砂糖の結晶（ロックキャンディ）?
The main materials required are: Granulated sugar, Water, Cotton string, Food coloring, Flavoring extract.
What results should I expect from 砂糖の結晶（ロックキャンディ）?
After 5-7 days, large sugar crystals (1-3 cm) should form along the string, creating rock candy. Crystals are monoclinic with flat, angled faces. The result is edible.