Хемилюминесценция с люминолом

Получение синего света в ходе химической реакции без нагрева

Classroom Demonstrations Intermediate (High School) 30 мин ~$15,00

Цель

Продемонстрировать хемилюминесценцию, окисляя люминол пероксидом водорода в присутствии катализатора и получая видимый синий свет.

Предпосылки

Luminol (3-aminophthalhydrazide) produces an eerie blue glow when oxidized by hydrogen peroxide in basic solution with a transition metal catalyst. The oxidation produces 3-aminophthalate in an excited electronic state, which releases energy as a photon of blue light (425 nm) as it returns to the ground state. This is the same reaction used by forensic scientists to detect trace amounts of blood at crime scenes, where the iron in hemoglobin acts as the catalyst.

Предупреждения по безопасности

  • NaOH is corrosive — handle with care
  • Potassium ferricyanide is harmful if ingested
  • Perform in a dark room for best effect
  • Do not mix stock solutions until ready to demonstrate

Требуемые СИЗ

goggles gloves lab_coat

Материалы

  • Luminol (0.5 g)
    3-aminophthalhydrazide
  • Sodium hydroxide (NaOH) (5 g)
    To make solution basic
  • Hydrogen peroxide (3%) (50 mL)
    Household concentration
  • Potassium ferricyanide (K₃[Fe(CN)₆]) (0.5 g)
    Catalyst
  • Distilled water (500 mL)

Оборудование

Beakers (500 mL, 2) Spiral glass tubing or clear tubing Dark room or blackout curtains Magnetic stirrer (optional)

Процедура

1

Prepare Solution A: Dissolve 0.5 g luminol and 5 g NaOH in 250 mL distilled water.

5 мин NaOH is corrosive
2

Prepare Solution B: Dissolve 0.5 g K₃[Fe(CN)₆] in 250 mL of 3% H₂O₂.

5 мин
3

Darken the room completely. Allow eyes to adjust for 1–2 minutes.

2 мин
4

Pour both solutions simultaneously into a large beaker or through spiral glass tubing. A bright blue glow appears immediately.

3 мин
5

Observe the glow lasting for several minutes. Stirring or agitation renews the glow by mixing fresh reactants.

10 мин
6

Discuss the mechanism: luminol oxidation → excited 3-aminophthalate → photon emission (425 nm). Compare with bioluminescence and fluorescence.

5 мин

Ожидаемые результаты

A vivid blue glow appears when the solutions are mixed. The light intensity peaks immediately and fades over several minutes. The glow is bright enough to read by in a completely dark room.

Уборка

The spent solution is relatively non-toxic. Pour down the drain with copious water. Rinse all glassware.

Детали

Категория
Classroom Demonstrations
Сложность
Intermediate (High School)
Продолжительность
30 мин
Прим. стоимость
$15,00
Шаги
6
Материалы
5

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Frequently Asked Questions

What is the objective of Хемилюминесценция с люминолом?
Продемонстрировать хемилюминесценцию, окисляя люминол пероксидом водорода в присутствии катализатора и получая видимый синий свет.
How difficult is Хемилюминесценция с люминолом?
This experiment is rated as Intermediate (High School). It takes approximately 30 minutes to complete.
What safety precautions are needed for Хемилюминесценция с люминолом?
Key safety precautions include: NaOH is corrosive — handle with care; Potassium ferricyanide is harmful if ingested; Perform in a dark room for best effect.
What materials are needed for Хемилюминесценция с люминолом?
The main materials required are: Luminol, Sodium hydroxide (NaOH), Hydrogen peroxide (3%), Potassium ferricyanide (K₃[Fe(CN)₆]), Distilled water.
What results should I expect from Хемилюминесценция с люминолом?
A vivid blue glow appears when the solutions are mixed. The light intensity peaks immediately and fades over several minutes. The glow is bright enough to read by in a completely dark room.