Organic Compounds
Organic molecules often show a dramatic increase in solubility with temperature, partly because of the polarity changes described above, and also because the solubility of sparingly soluble materials tends to increase with temperature as they have a high enthalpy of solution. Thus materials generally considered “insoluble” can become soluble in superheated water. E.g., the solubility of PAHs is increased by 5 orders of magnitude from 25 °C to 225 °C and naphthalene, for example, forms a 10% wt solution in water at 270 °C, and the solubility of the pesticide chloranthonil with temperature is shown in the table below.
| T (°C) | Mole Fraction |
|---|---|
| 50 | 5.41 x 10−8 |
| 100 | 1.8 x 10−6 |
| 150 | 6.43 x 10−5 |
| 200 | 1.58 x 10−3 |
Thus superheated water can be used to process many organic compounds with significant environmental benefits compared to the use of conventional organic solvents.
Read more about this topic: Superheated Water, Solubility
Famous quotes containing the words organic and/or compounds:
“The human face is the organic seat of beauty.... It is the register of value in development, a record of Experience, whose legitimate office is to perfect the life, a legible language to those who will study it, of the majestic mistress, the soul.”
—Eliza Farnham (1815–1864)
“We can come up with a working definition of life, which is what we did for the Viking mission to Mars. We said we could think in terms of a large molecule made up of carbon compounds that can replicate, or make copies of itself, and metabolize food and energy. So that’s the thought: macrocolecule, metabolism, replication.”
—Cyril Ponnamperuma (b. 1923)