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[9] [10] [11] Both of them obtained piperidine by reacting piperine with nitric acid. Industrially, piperidine is produced by the hydrogenation of pyridine, usually over a molybdenum disulfide catalyst: [12] C 5 H 5 N + 3 H 2 → C 5 H 10 NH. Pyridine can also be reduced to piperidine via a modified Birch reduction using sodium in ethanol. [13]
The following chart shows the solubility of various ionic compounds in water at 1 atm pressure and room temperature (approx. 25 °C, 298.15 K). "Soluble" means the ionic compound doesn't precipitate, while "slightly soluble" and "insoluble" mean that a solid will precipitate; "slightly soluble" compounds like calcium sulfate may require heat to precipitate.
For comparison, crystalline benzene is also orthorhombic, with space group Pbca, a = 729.2 pm, b = 947.1 pm, c = 674.2 pm (at 78 K), but the number of molecules per cell is only 4. [18] This difference is partly related to the lower symmetry of the individual pyridine molecule (C 2v vs D 6h for benzene).
Due to its poor solubility in water, piperine is typically extracted from black pepper by using organic solvents like dichloromethane. [5] The amount of piperine varies from 1–2% in long pepper, to 5–10% in commercial white and black peppers.
Note that the especially high molar values, as for paraffin, gasoline, water and ammonia, result from calculating specific heats in terms of moles of molecules. If specific heat is expressed per mole of atoms for these substances, none of the constant-volume values exceed, to any large extent, the theoretical Dulong–Petit limit of 25 J⋅mol ...
The nearer two molecules are in this three-dimensional space, the more likely they are to dissolve into each other. To determine if the parameters of two molecules (usually a solvent and a polymer) are within range, a value called interaction radius ( R 0 {\displaystyle R_{\mathrm {0} }} ) is given to the substance being dissolved.
Specific gravity is defined as the density of the solvent divided by the density of water at the same temperature. As such, specific gravity is a unitless value. It readily communicates whether a water-insoluble solvent will float (SG < 1.0) or sink (SG > 1.0) when mixed with water.
A sodium ion solvated by water molecules. Solvations describes the interaction of a solvent with dissolved molecules. Both ionized and uncharged molecules interact strongly with a solvent, and the strength and nature of this interaction influence many properties of the solute, including solubility, reactivity, and color, as well as influencing the properties of the solvent such as its ...