Flower Color Change Demonstration as a Visualization of Potential Harmful Effects Associated with Ammonia Gas on Living Organisms

Abstract

This manuscript describes a simple yet meaningful demonstration that can be easily adopted by highschool teachers to emphasize some potential dangers associated with gas inhalation. The demonstration aims to illustrate the undesirable effects of some gases on living organisms by employing freshly cut, colored flowers and ammonia gas. When in direct contact, the ammonia gas causes abrupt, easily observable changes in the appearances of the flowers, leading to their wilting, discoloration, or color fading. The experiment can be carried out at any time within an academic course because flowers with colorful petals can be easily obtained from any local store throughout the year. The proposed demonstration may also be used, if necessary, to introduce students into important biological and chemical concepts, including simple chemical calculations, the cell structure of flowers, and the effects of harmful gas molecules on living cells.

Demonstrating Purple Color Development to Students by Showing the Highly Visual Effects of Aluminum Ions and pH on Aqueous Anthocyanin Solutions

“…However, at neutral and higher pH, the color is not stable. The anthocyanin molecule undergoes hydration, e.g., the formation of a pseudobase. ,, At strongly acidic pH, no fading was observed in the absence of neochlorogenic acid due to the formation of stable flavylium ions. ,, …”

“…15 Such activity has been expanded via internet links 16 and connected with art, 17 biology, 18 drinks, 19 antioxidants, 20 fermentation, 21 and gas inhalation. 22 Recently, the coloration of anthocyanin by complexation with metal ions was reported in this Journal: the red band in the chromatogram changes to a blue band. 23 This coloration mechanism is different from the well-known pH-indicator mechanism.…”

“…22,24,48 At strongly acidic pH, no fading was observed in the absence of neochlorogenic acid due to the formation of stable flavylium ions. 22,24,48…”

“…As an acid–base indicator, anthocyanins produce a variety of colors in leaves and plants and have been utilized as educational materials in the making of colorful paper, sensors, chameleon balls, chromatograms, and solar cells . Such activity has been expanded via internet links and connected with art, biology, drinks, antioxidants, fermentation, and gas inhalation . Recently, the coloration of anthocyanin by complexation with metal ions was reported in this Journal : the red band in the chromatogram changes to a blue band .…”

Separation of Anthocyaninic and Nonanthocyaninic Flavonoids by Liquid–Liquid Extraction Based on Their Acid–Base Properties: A Green Chemistry Approach

“…Likewise, daily applications of natural anthocyanins include dye-sensitized solar cells and pH indicators in films for food packaging . As laboratory experiments for practical classes must be based on green chemistry pedagogic activities, natural anthocyanins have been extensively suggested for laboratory activities aiming to teach acid–base equilibria in classes. ,,− …”