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In 1871 he discovered the synthesis of phenolphthalein by condensation of phthalic anhydride with two equivalents of phenol under acidic conditions (hence the name). That same year he was the first to obtain synthetic fluorescein , a fluorophore pigment which is similar to naturally occurring pyoverdin that is synthesised by microorganisms (e.g ...
Phenolphthalein is slightly soluble in water and usually is dissolved in alcohols in experiments. It is a weak acid, which can lose H + ions in solution. The nonionized phenolphthalein molecule is colorless and the double deprotonated phenolphthalein ion is fuchsia. Further proton loss in higher pH occurs slowly and leads to a colorless form.
Phenolphthalein can be synthesized by the condensation of phthalic anhydride with two equivalents of phenol under acidic conditions (hence the name). It was discovered in 1871 by Adolf von Baeyer. [8] [9] [10] Synthesis of phenolphthalein [11]
Phenolphthalein does not directly participate in this process; instead, it acts as an external source of electrons. In its reaction with hydrogen peroxide, the heme center of hemoglobin behaves as a peroxidase, reducing the peroxide to water. This activity depletes hemoglobin of electrons that are, in turn, re-supplied by the phenolphthalein.
Joseph Priestley FRS (/ ˈ p r iː s t l i /; [3] 24 March 1733 – 6 February 1804) was an English chemist, Unitarian, natural philosopher, separatist theologian, grammarian, multi-subject educator and classical liberal political theorist. [4]
Friedrich Wilhelm Ostwald (German: [ˈvɪlhɛlm ˈɔstˌvalt] ⓘ; 2 September [O.S. 21 August] 1853 – 4 April 1932) was a German chemist and philosopher.Ostwald is credited with being one of the founders of the field of physical chemistry, with Jacobus Henricus van 't Hoff, Walther Nernst and Svante Arrhenius. [1]
Multiple wildfires across Los Angeles have caused widespread devastation and killed 24 people. The fires have burned over 40,000 acres as high winds have made them difficult to contain.
Michael Sendivogius (/ ˌ s ɛ n d ɪ ˈ v oʊ dʒ i ə s /; Polish: Michał Sędziwój; 2 February 1566 – 1636) was a Polish alchemist, philosopher, and medical doctor.A pioneer of chemistry, he developed ways of purification and creation of various acids, metals and other chemical compounds.