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A related ring-opening reaction involves peroxides to give the useful peroxy acid: [16] C 6 H 4 (CO) 2 O + H 2 O 2 → C 6 H 4 (CO 3 H)CO 2 H. Phthalimide can be prepared by heating phthalic anhydride with aqueous ammonia giving a 95–97% yield. Alternatively, it may be prepared by treating the anhydride with ammonium carbonate or urea.
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.
Chemical structure of phenolphthalein, a common phthalein dye. Phthalein dyes are a class of dyes mainly used as pH indicators, due to their ability to change colors depending on pH. [1] They are formed by the reaction of phthalic anhydride with various phenols. They are a subclass of triarylmethane dyes. Common phthalein dyes include ...
The reaction between a ketone and ammonia results in an imine and byproduct water. This reaction is water sensitive and thus drying agents such as aluminum chloride or a Dean–Stark apparatus must be employed to remove water. The resulting imine will react and decompose back into the ketone and the ammonia when in the presence of water.
An analogous reaction occurs in liquid ammonia + + + Thus, the ammonium ion, NH + 4, in liquid ammonia corresponds to the hydronium ion in water and the amide ion, NH − 2 in ammonia, to the hydroxide ion in water. Ammonium salts behave as acids, and metal amides behave as bases. [10]
Phenol in the Berthelot reagent can be replaced by a variety of phenolic reagents, the most common being sodium salicylate, which is significantly less toxic. [1] This has been used for blood urea nitrogen (BUN) determinations and commonly is used to determine water and soil total and ammonia-N. Replacement of phenol by 2-phenylphenol reduces interferences by a variety of soil and water ...
For instance, ammonia gas, which is alkaline, turns red litmus paper blue. While all litmus paper acts as pH paper, the opposite is not true. Litmus can also be prepared as an aqueous solution that functions similarly. Under acidic conditions, the solution is red, and under alkaline conditions, the solution is blue.
Ammonia is a direct or indirect precursor to most manufactured nitrogen-containing compounds. It is the precursor to nitric acid, which is the source for most N-substituted aromatic compounds. Amines can be formed by the reaction of ammonia with alkyl halides or, more commonly, with alcohols: CH 3 OH + NH 3 → CH 3 NH 2 + H 2 O