Test de Flamme au Sodium

Identification du sodium par sa flamme jaune vif

Flame Tests Beginner (Middle School) 15 min ~$5,00

Objectif

Observer la flamme jaune vif caractéristique produite lors de la chauffe de composés sodiques, démontrant comment les ions métalliques produisent des couleurs de flamme spécifiques.

Contexte

The sodium flame test is one of the simplest and most dramatic qualitative analysis techniques. When sodium ions are introduced into a flame, the thermal energy excites the 3s valence electron to the 3p orbital. As the electron returns to the ground state, it emits light at 589 nm, producing an intense and persistent yellow-orange color. This is the same emission responsible for the yellow color of sodium vapor street lamps.

Avertissements de sécurité

  • Wear safety goggles at all times
  • Keep hair tied back near open flames
  • Handle HCl with care — avoid skin contact
  • Ensure proper ventilation

EPI requis

goggles lab_coat

Matériaux

  • Sodium chloride (NaCl) (1 g)
    Table salt works
  • Hydrochloric acid (HCl) (10 mL)
    1M concentration
  • Distilled water (50 mL)
    For cleaning

Équipement

Bunsen burner Nichrome wire loop Watch glass Forceps

Procédure

1

Clean the nichrome wire by dipping it in 1M HCl and holding it in the hottest part of the Bunsen burner flame. Repeat until no color appears in the flame.

2 min
2

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

1 min
3

Dip the clean nichrome wire into the HCl, then into the sodium chloride sample to pick up a small amount.

1 min
4

Hold the wire loop with the sample at the edge of the Bunsen burner flame and observe the flame color.

2 min Keep face away from flame
5

Record the flame color observed. Note the intensity and persistence of the color.

1 min
6

Clean the wire again with HCl and repeat to confirm results.

2 min

Résultats attendus

A bright, persistent yellow-orange flame should appear immediately when the sodium chloride is introduced to the flame. The color is so intense that it can mask the colors of other metal ions present.

Nettoyage

Clean the nichrome wire loop thoroughly with HCl. Dispose of remaining chemicals according to lab protocols. Wipe down the work area.

Détails

Catégorie
Flame Tests
Difficulté
Beginner (Middle School)
Durée
15 min
Coût estimé
$5,00
Étapes
6
Matériaux
3

Plus d'expériences

Laboratoire de Comparaison des Tests de Flamme 45 min Test de Flamme au Baryum 20 min Test de Flamme au Calcium 15 min Test de Flamme au Cuivre 15 min Test de Flamme au Lithium 15 min Test de Flamme au Potassium 20 min Test de Flamme au Strontium 15 min

Frequently Asked Questions

What is the objective of Test de Flamme au Sodium?
Observer la flamme jaune vif caractéristique produite lors de la chauffe de composés sodiques, démontrant comment les ions métalliques produisent des couleurs de flamme spécifiques.
How difficult is Test de Flamme au Sodium?
This experiment is rated as Beginner (Middle School). It takes approximately 15 minutes to complete.
What safety precautions are needed for Test de Flamme au Sodium?
Key safety precautions include: Wear safety goggles at all times; Keep hair tied back near open flames; Handle HCl with care — avoid skin contact.
What materials are needed for Test de Flamme au Sodium?
The main materials required are: Sodium chloride (NaCl), Hydrochloric acid (HCl), Distilled water.
What results should I expect from Test de Flamme au Sodium?
A bright, persistent yellow-orange flame should appear immediately when the sodium chloride is introduced to the flame. The color is so intense that it can mask the colors of other metal ions present.