Prueba de Llama con Potasio

Identificación del potasio por su llama lila/violeta

Flame Tests Beginner (Middle School) 20 min ~$6,00

Objetivo

Observar el color de llama lila/violeta producido por los iones de potasio, y aprender a usar vidrio azul cobalto para distinguirlo de la contaminación por sodio.

Antecedentes

Potassium produces a pale lilac or violet flame when heated. The emission occurs at 766.5 nm and 769.9 nm (near-infrared/deep red doublet). Because the flame is quite faint and easily overwhelmed by sodium's intense yellow, cobalt blue glass is used as a filter to block sodium emission and reveal potassium's true color.

Advertencias de seguridad

  • Wear safety goggles at all times
  • Keep hair tied back near open flames
  • Handle HCl with care

EPP requerido

goggles lab_coat

Materiales

  • Potassium chloride (KCl) (1 g)
  • Hydrochloric acid (HCl) (10 mL)
    1M concentration
  • Cobalt blue glass (1 piece)
    For filtering sodium light

Equipamiento

Bunsen burner Nichrome wire loop Watch glass Forceps

Procedimiento

1

Clean the nichrome wire thoroughly by dipping in HCl and heating.

2 min
2

Place potassium chloride on the watch glass and collect a sample on the clean wire.

1 min
3

Hold the sample in the Bunsen burner flame. Observe with the naked eye first.

2 min
4

Now observe the flame through cobalt blue glass to filter out any sodium contamination.

2 min
5

Record the difference in appearance with and without the cobalt blue glass filter.

2 min

Resultados esperados

Without the filter, you may see a faint lilac color possibly masked by yellow from sodium impurities. Through the cobalt blue glass, a clear violet/lilac flame should be visible as the glass absorbs the yellow sodium emission.

Limpieza

Clean the wire loop with HCl. Return cobalt blue glass to storage.

Detalles

Categoría
Flame Tests
Dificultad
Beginner (Middle School)
Duración
20 min
Costo estimado
$6,00
Pasos
5
Materiales
3

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Frequently Asked Questions

What is the objective of Prueba de Llama con Potasio?
Observar el color de llama lila/violeta producido por los iones de potasio, y aprender a usar vidrio azul cobalto para distinguirlo de la contaminación por sodio.
How difficult is Prueba de Llama con Potasio?
This experiment is rated as Beginner (Middle School). It takes approximately 20 minutes to complete.
What safety precautions are needed for Prueba de Llama con Potasio?
Key safety precautions include: Wear safety goggles at all times; Keep hair tied back near open flames; Handle HCl with care.
What materials are needed for Prueba de Llama con Potasio?
The main materials required are: Potassium chloride (KCl), Hydrochloric acid (HCl), Cobalt blue glass.
What results should I expect from Prueba de Llama con Potasio?
Without the filter, you may see a faint lilac color possibly masked by yellow from sodium impurities. Through the cobalt blue glass, a clear violet/lilac flame should be visible as the glass absorbs the yellow sodium emission.