Teste de Chama do Bário

Identificação do bário pela sua chama amarelo-esverdeada

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

Objetivo

Observar a pálida chama amarelo-esverdeada produzida pelos íons de bário e entender por que os compostos de bário requerem precauções de segurança adicionais.

Contexto

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.

Avisos de segurança

  • 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 necessário

goggles gloves lab_coat

Materiais

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

Equipamentos

Bunsen burner Nichrome wire loop Watch glass Forceps

Procedimento

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

Resultados esperados

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.

Limpeza

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

Detalhes

Categoria
Flame Tests
Dificuldade
Intermediate (High School)
Duração
20 min
Custo estimado
$12,00
Passos
6
Materiais
3

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Frequently Asked Questions

What is the objective of Teste de Chama do Bário?
Observar a pálida chama amarelo-esverdeada produzida pelos íons de bário e entender por que os compostos de bário requerem precauções de segurança adicionais.
How difficult is Teste de Chama do Bário?
This experiment is rated as Intermediate (High School). It takes approximately 20 minutes to complete.
What safety precautions are needed for Teste de Chama do Bário?
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 Teste de Chama do Bário?
The main materials required are: Barium chloride (BaCl₂), Hydrochloric acid (HCl), Distilled water.
What results should I expect from Teste de Chama do Bário?
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.