Калиевый пламенный тест

Определение калия по сиреневому/фиолетовому пламени

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

Цель

Наблюдать сиреневый/фиолетовый цвет пламени ионов калия и научиться использовать кобальтово-синее стекло для отличия от примеси натрия.

Предпосылки

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.

Предупреждения по безопасности

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

Требуемые СИЗ

goggles lab_coat

Материалы

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

Оборудование

Bunsen burner Nichrome wire loop Watch glass Forceps

Процедура

1

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

2 мин
2

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

1 мин
3

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

2 мин
4

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

2 мин
5

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

2 мин

Ожидаемые результаты

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.

Уборка

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

Детали

Категория
Flame Tests
Сложность
Beginner (Middle School)
Продолжительность
20 мин
Прим. стоимость
$6,00
Шаги
5
Материалы
3

Ещё эксперименты

Бариевый пламенный тест 20 min Кальциевый пламенный тест 15 min Литиевый пламенный тест 15 min Медный пламенный тест 15 min Натриевый пламенный тест 15 min Сравнительная лаборатория пламенных тестов 45 min Стронциевый пламенный тест 15 min

Frequently Asked Questions

What is the objective of Калиевый пламенный тест?
Наблюдать сиреневый/фиолетовый цвет пламени ионов калия и научиться использовать кобальтово-синее стекло для отличия от примеси натрия.
How difficult is Калиевый пламенный тест?
This experiment is rated as Beginner (Middle School). It takes approximately 20 minutes to complete.
What safety precautions are needed for Калиевый пламенный тест?
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 Калиевый пламенный тест?
The main materials required are: Potassium chloride (KCl), Hydrochloric acid (HCl), Cobalt blue glass.
What results should I expect from Калиевый пламенный тест?
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.