- 作者: M. E. Soltan* and S. M. Sirry
- 作者服務機構: Chemistry Department, Faculty of Science, South Valley University, Aswan, Egypt
- 中文摘要: Environmental protection must require the use of natural products instead of chemicals to minimize pollution. Thus, this investigation studies the use of some plant flowers as naturally occurring acid-base indicators. We utilized plant flowers of Celosia cristate Linn, Bombax ceiba L., Poinciana regia and Hibiscus subdariffa. These flowers contain anthocyanine pigments whose colour depends on pH; therefore they are used as pH indicators. The acid-base equilibria of these pigments were investigated using spectrophotometric and potentiometric methods. The pk values are 9.6 for Celosia cristate Linn, 5.7 for Bombax ceiba L., 8.6 for Poinciana regia and 2.8 & 7.3 for Hibiscus subdariffa. Experimentation of these indicators on different concentrations of acid-base titrations in the presence of variable concentrations exhibited similar results as for synthetic indicators.
- 英文摘要: --
- 中文關鍵字: Plant flowers; Natural indicators; Acid-base equilibria.
- 英文關鍵字: Plant flowers; Natural indicators; Acid-base equilibria.