ハロゲンのバイルシュタイン試験

銅線炎色反応で有機化合物中のハロゲン原子を検出する

Qualitative Analysis Beginner (Middle School) 25 分 ~$5.00

目的

バイルシュタイン銅線試験を用いて有機化合物にハロゲン原子（Cl、Br、I）が含まれるかどうかを決定する。

背景

The Beilstein test is a simple qualitative test for halogens in organic compounds. A copper wire is heated in a flame to form copper(II) oxide, then dipped in the test substance and returned to the flame. If a halogen is present, volatile copper halide forms and imparts a green or blue-green color to the flame. The test is sensitive but not specific (it does not distinguish between Cl, Br, and I, and can give false positives with some nitrogen compounds).

安全上の警告

  • Chloroform is toxic — avoid inhalation and skin contact
  • Work in a fume hood when testing volatile organics
  • Hot copper wire can cause burns
  • Keep flammable solvents away from the flame

必要なPPE

goggles gloves lab_coat

材料

  • Copper wire (20 gauge) (15 cm)
    Make a small loop at one end
  • Chloroform (CHCl₃) (2 mL)
    Positive control
  • Ethanol (C₂H₅OH) (2 mL)
    Negative control
  • Unknown organic samples (2 mL each)
    3–4 samples
  • Cork or holder for copper wire (1)

器具

Bunsen burner Watch glasses (6) Forceps

手順

1

Heat the copper wire loop in the oxidizing zone of the Bunsen burner until it glows red and no green color is visible (this burns off contaminants and forms CuO).

3 分 Wire is extremely hot
2

Allow the wire to cool slightly, then dip it into the chloroform (positive control). Return the wire to the flame.

3 分 Chloroform is volatile — use fume hood
3

Observe the bright green flame (positive result for halogen). Record the color and intensity.

2 分
4

Clean the wire by heating until green color disappears. Repeat the test with ethanol (negative control). No green color should appear.

3 分
5

Test each unknown sample using the same procedure. Record whether each gives a positive (green) or negative result.

10 分 Clean wire between samples
6

Record all results and identify which unknowns likely contain halogen atoms.

4 分

予想される結果

Chloroform produces a vivid green flame (positive). Ethanol produces no green color (negative). Halogen-containing unknowns show green coloration of varying intensity.

後片付け

Allow copper wire to cool. Store organic waste in halogenated or non-halogenated solvent waste containers as appropriate. Wipe down surfaces.

詳細

カテゴリ
Qualitative Analysis
難易度
Beginner (Middle School)
所要時間
25 分
推定費用
$5.00
ステップ数
6
材料
5

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Frequently Asked Questions

What is the objective of ハロゲンのバイルシュタイン試験?
バイルシュタイン銅線試験を用いて有機化合物にハロゲン原子（Cl、Br、I）が含まれるかどうかを決定する。
How difficult is ハロゲンのバイルシュタイン試験?
This experiment is rated as Beginner (Middle School). It takes approximately 25 minutes to complete.
What safety precautions are needed for ハロゲンのバイルシュタイン試験?
Key safety precautions include: Chloroform is toxic — avoid inhalation and skin contact; Work in a fume hood when testing volatile organics; Hot copper wire can cause burns.
What materials are needed for ハロゲンのバイルシュタイン試験?
The main materials required are: Copper wire (20 gauge), Chloroform (CHCl₃), Ethanol (C₂H₅OH), Unknown organic samples, Cork or holder for copper wire.
What results should I expect from ハロゲンのバイルシュタイン試験?
Chloroform produces a vivid green flame (positive). Ethanol produces no green color (negative). Halogen-containing unknowns show green coloration of varying intensity.