हैलोजन के लिए बेल्स्टीन परीक्षण

तांबे के तार ज्वाला परीक्षण का उपयोग करके कार्बनिक यौगिकों में हैलोजन परमाणुओं का पता लगाना

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

उद्देश्य

बेल्स्टीन तांबे के तार परीक्षण का उपयोग करके निर्धारित करें कि कोई कार्बनिक यौगिक हैलोजन परमाणु (Cl, Br, I) युक्त है या नहीं।

पृष्ठभूमि

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).

सुरक्षा चेतावनियाँ

  • 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

आवश्यक PPE

goggles gloves lab_coat

सामग्री

  • 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)

उपकरण

Bunsen burner Watch glasses (6) Forceps

प्रक्रिया

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 मिनट 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 मिनट Chloroform is volatile — use fume hood
3

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

2 मिनट
4

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

3 मिनट
5

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

10 मिनट Clean wire between samples
6

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

4 मिनट

अपेक्षित परिणाम

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

सफाई

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

Frequently Asked Questions

What is the objective of हैलोजन के लिए बेल्स्टीन परीक्षण?
बेल्स्टीन तांबे के तार परीक्षण का उपयोग करके निर्धारित करें कि कोई कार्बनिक यौगिक हैलोजन परमाणु (Cl, Br, I) युक्त है या नहीं।
How difficult is हैलोजन के लिए बेल्स्टीन परीक्षण?
This experiment is rated as Beginner (Middle School). It takes approximately 25 minutes to complete.
What safety precautions are needed for हैलोजन के लिए बेल्स्टीन परीक्षण?
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 हैलोजन के लिए बेल्स्टीन परीक्षण?
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 हैलोजन के लिए बेल्स्टीन परीक्षण?
Chloroform produces a vivid green flame (positive). Ethanol produces no green color (negative). Halogen-containing unknowns show green coloration of varying intensity.