Test de Flamme au Baryum

Identification du baryum par sa flamme jaune-verte

Flame Tests Intermediate (High School) 20 min ~$12,00

Objectif

Observer la pâle flamme jaune-verte produite par les ions baryum et comprendre pourquoi les composés barytiques nécessitent des précautions de sécurité supplémentaires.

Contexte

Barium compounds produce a pale yellow-green (apple-green) flame when heated. The emission is primarily from BaCl molecules formed in the flame rather than from atomic barium. Barium compounds are toxic and require careful handling, but the flame test itself uses small quantities safely.

Avertissements de sécurité

  • Barium chloride is toxic if ingested
  • Wear nitrile gloves when handling barium compounds
  • Wear safety goggles at all times
  • Wash hands thoroughly after the experiment
  • Do not eat or drink in the lab

EPI requis

goggles gloves lab_coat

Matériaux

  • Barium chloride (BaCl₂) (0.5 g)
    Toxic — handle with care
  • Hydrochloric acid (HCl) (10 mL)
    1M concentration
  • Distilled water (50 mL)
    For cleaning

Équipement

Bunsen burner Nichrome wire loop Watch glass Forceps

Procédure

1

Put on nitrile gloves before handling barium chloride.

1 min Barium compounds are toxic
2

Clean the nichrome wire by dipping in HCl and heating until no color appears.

2 min
3

Place a small amount of barium chloride on the watch glass.

1 min Avoid skin contact
4

Dip the clean wire into HCl, then into the barium chloride sample.

1 min
5

Hold the wire in the Bunsen burner flame and observe the pale yellow-green color.

2 min
6

Record the color and compare with copper (blue-green) if previously tested.

2 min

Résultats attendus

A pale yellow-green (apple-green) flame should appear. The color is less vivid than copper's blue-green and has a distinctly yellowish tint. It may be difficult to see in a well-lit room.

Nettoyage

Clean the wire with HCl. Dispose of barium waste in designated heavy metal waste container. Remove gloves carefully and wash hands thoroughly.

Détails

Catégorie
Flame Tests
Difficulté
Intermediate (High School)
Durée
20 min
Coût estimé
$12,00
Étapes
6
Matériaux
3

Plus d'expériences

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Frequently Asked Questions

What is the objective of Test de Flamme au Baryum?
Observer la pâle flamme jaune-verte produite par les ions baryum et comprendre pourquoi les composés barytiques nécessitent des précautions de sécurité supplémentaires.
How difficult is Test de Flamme au Baryum?
This experiment is rated as Intermediate (High School). It takes approximately 20 minutes to complete.
What safety precautions are needed for Test de Flamme au Baryum?
Key safety precautions include: Barium chloride is toxic if ingested; Wear nitrile gloves when handling barium compounds; Wear safety goggles at all times.
What materials are needed for Test de Flamme au Baryum?
The main materials required are: Barium chloride (BaCl₂), Hydrochloric acid (HCl), Distilled water.
What results should I expect from Test de Flamme au Baryum?
A pale yellow-green (apple-green) flame should appear. The color is less vivid than copper's blue-green and has a distinctly yellowish tint. It may be difficult to see in a well-lit room.