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10 hours ago · The solvent, dichloromethane, has a boiling point of 39.6 °C, which is closer to the boiling points of these 3 compounds (which is not the case with the remaining compounds). Hence, a slower ramp rate (5 °C/min) was required for the identification and quantification of pyridine.
10 hours ago · The acid values recorded for the shea kernel oil in this study ranged from (29.1- 41.5 mgKOH/g) and (5.27-7.52 mgKOH/g) for n-hexane and petroleum ether respectively. The acids values for the n-hexane were higher than that of the petroleum ether. The results showed that the acid values depend on the type of solvent just as the yield.
10 hours ago · In most cases, they are in the normal UV spectral range (λ > 200 nm). 64 The length, the topology, and the conformation of the silicon chain are influencing factors on the position of the UV absorption. 65, 66 Furthermore, the type of substituents on the silicon atoms do influence the position and intensity of the absorption bands. 67 The ...
10 hours ago · Boiling Point: Approximately 249°C. pKa: 4.19. Density: 1.27 g/cm3. Chemical Properties. Stability: Benzoic acid exhibits high stability under normal conditions and is not easily decomposed. Acidity: It is a weak acid, thus capable of donating hydrogen ions (H+) to form benzoate ions. pH Value: As a weak acid, its pH is approximately 2.8.
10 hours ago · Such ice is an amorphous solid form of water, which lacks long-range order in its molecular arrangement. Amorphous ice is produced either by rapid cooling of liquid water to its glass transition temperature (about 136 K or −137 °C) in milliseconds (so the molecules do not have enough time to form a crystal lattice ), or by compressing ...
10 hours ago · Hong Kong officially launches pilot for digital yuan payments
10 hours ago · Chalcone (1,3-diaryl-2-propen-1-one) is an α, β-unsaturated ketone that serves as an active constituent or precursor of numerous natural substances, exhibiting a broad spectrum of pharmacological effects. In this study, the classical Claisen–Schmidt condensation method was used to synthesize the chalcone derivative 2′,4′-dimethoxychalcone (DTC) and evaluate its pharmacological activity ...
