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4-Aminophenol (or para-aminophenol or p-aminophenol) is an organic compound with the formula H 2 NC 6 H 4 OH. Typically available as a white powder, [ 3 ] it is commonly used as a developer for black-and-white film , marketed under the name Rodinal .
The Gmelin rare earths handbook lists 1522 °C and 1550 °C as two melting points given in the literature, the most recent reference [Handbook on the chemistry and physics of rare earths, vol.12 (1989)] is given with 1529 °C.
4-Aminophenol may be obtained by the amide hydrolysis of paracetamol. This reaction is also used to determine paracetamol in urine samples: After hydrolysis with hydrochloric acid, 4-aminophenol reacts in ammonia solution with a phenol derivate, e.g. salicylic acid, to form an indophenol dye under oxidization by air. [139]
Morpholine is an organic chemical compound having the chemical formula O(C H 2 CH 2) 2 NH. This heterocycle features both amine and ether functional groups.Because of the amine, morpholine is a base; its conjugate acid is called morpholinium.
4-Aminobiphenyl (4-ABP) is an organic compound with the formula C 6 H 5 C 6 H 4 NH 2. It is an amine derivative of biphenyl . It is a colorless solid, although aged samples can appear colored. 4-Aminobiphenyl was commonly used in the past as a rubber antioxidant and an intermediate for dyes. [ 5 ]
At the temperature of the melting point, 0 °C, the chemical potentials in water and ice are the same; the ice cube neither grows nor shrinks, and the system is in equilibrium. A third example is illustrated by the chemical reaction of dissociation of a weak acid HA (such as acetic acid, A = CH 3 COO −): HA ⇌ H + + A −. Vinegar contains ...
The melting point (or, rarely, liquefaction point) of a substance is the temperature at which it changes state from solid to liquid. At the melting point the solid and liquid phase exist in equilibrium. The melting point of a substance depends on pressure and is usually specified at a standard pressure such as 1 atmosphere or 100 kPa.
In alkaline solution, pyrogallol undergoes deprotonation. Such solutions absorb oxygen from the air, turning brown. This conversion can be used to determine the amount of oxygen in a gas sample, notably by the use of the Orsat apparatus. Alkaline solutions of pyrogallol have been used for oxygen absorption in gas analysis.