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Starch gelatinization is a process of breaking down of intermolecular bonds of starch molecules in the presence of water and heat, allowing the hydrogen bonding sites (the hydroxyl hydrogen and oxygen) to engage more water. This irreversibly dissolves the starch granule in water. Water acts as a plasticizer.
The phenomenon, when taken to mean "hot water freezes faster than cold", is difficult to reproduce or confirm because it is ill-defined. [4] Monwhea Jeng proposed a more precise wording: "There exists a set of initial parameters, and a pair of temperatures, such that given two bodies of water identical in these parameters, and differing only in initial uniform temperatures, the hot one will ...
Efficient and economical water splitting would be a technological breakthrough that could underpin a hydrogen economy. A version of water splitting occurs in photosynthesis, but hydrogen is not produced. The reverse of water splitting is the basis of the hydrogen fuel cell. Water splitting using solar radiation has not been commercialized.
A catalyst is required to make the process operate at feasible temperatures. Heating the water can be achieved through the use of water concentrating solar power. Hydrosol-2 is a 100-kilowatt pilot plant at the Plataforma Solar de Almería in Spain which uses sunlight to obtain the required 800 to 1,200 °C to heat water. Hydrosol II has been ...
Pure water has a charge carrier density similar to semiconductors [12] [page needed] since it has a low autoionization, K w = 1.0×10 −14 at room temperature and thus pure water conducts current poorly, 0.055 μS/cm. [13] Unless a large potential is applied to increase the autoionization of water, electrolysis of pure water proceeds slowly ...
In the hydrogenation of vegetable oils and fatty acids, for example, the heat released, about 25 kcal per mole (105 kJ/mol), is sufficient to raise the temperature of the oil by 1.6–1.7 °C per iodine number drop.
Since these systems do not work by exchanging ions, like traditional water softeners do, one benefit claimed for the user is the elimination of the need to add salt to the system. Such systems do not remove minerals from the water itself. Rather, they can only alter the downstream effects that the mineral-bearing water would otherwise have.
Thermochemistry is the study of the heat energy which is associated with chemical reactions and/or phase changes such as melting and boiling. A reaction may release or absorb energy, and a phase change may do the same. Thermochemistry focuses on the energy exchange between a system and its surroundings in the form of heat. Thermochemistry is ...