Color Changing Flowers

Flowers change their initial color under action of a volatile liquid.

Scientific name: Flowers pigments acts like acid-base indicators and change their color according to the pH shift.

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Chemie Experiment 60 - "Die verzauberte Rose"

Цветы меняют цвет - химические опыты

Free Range Chemistry 15 - Rose in Ammonia

by Royal Society Of Chemistry

Safety

Wear eye protection goggles.This experiment should be performed in a well-ventilated room or outdoors.

Always follow general safety recommendations. Please note that conducting chemistry experiments you must comply with the relevant legal procedures in your country.

Reaction formula

anthocyanin (violet) →(pH change)→ anthocyanin (colored)

Step-by-step instruction

  1. This experiment should be performed in a well-ventilated room.
  2. Prepare three cloves of different color (white, red and yellow). You also can use other flowers such as violets and red roses.
  3. Prepare a large glass.
  4. Pour the solution of household ammonia to cover the bottom. Add some amount of diethyl ether.
  5. Place the flowers in the glass, heads down, but so that they do not touch the liquid.
  6. Cover the glass and wait for some time.
  7. After a while take out the flowers. They change color.

Scientific background

Anthocyanins are common pigments of many flowers. The red color of rose petals and blue color of violets are caused by their presence. The color of anthocyanins could vary according to the presence of acids and bases. Pigment is pink at low pH, purple at neutral and greenish-yellow at high pH. This ability allows using it as an acid-base indicator. In the experiment under study the whole flower acts as litmus paper. The mixture used in the experiment is highly volatile. Ammonia is a base and shifts pH to alkaline turning violets from blue to green and yellow. At the same time, diethyl ether vapors promote the extraction of pigments from plant cells. Most of purple and pink flowers in alkaline medium turn to bright green. White flowers become yellow. Red autumn leaves turn green instantly. But yellow flowers such as buttercups and marigolds do not change their color. The only effect is that they become a little bit brighter. The reason is that some of yellow flowers do not contain anthocyanins as a dye. Their color is determined by other organic pigments – carotenoids. They also undergo some changes when pH turns to alkaline but they are not so dramatic.

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Published on 15 June 2015

  • Fire
  • Heating with fire
  • Explosion
  • Poisoned gas
  • Organic
  • Electricity
  • Solution
  • Oxidation reduction
  • Color change
  • Precipitate
  • Gassing
  • Catalyst