Search results
Results from the WOW.Com Content Network
The temperature of liquid nitrogen can readily be reduced to its freezing point −210 °C (−346 °F; 63 K) by placing it in a vacuum chamber pumped by a vacuum pump. [2] Liquid nitrogen's efficiency as a coolant is limited by the fact that it boils immediately on contact with a warmer object, enveloping the object in an insulating layer of ...
Water is the medium of the oceans, the medium which carries all the substances and elements involved in the marine biogeochemical cycles. Water as found in nature almost always includes dissolved substances, so water has been described as the "universal solvent" for its ability to dissolve so many substances.
Hydration energy is one component in the quantitative analysis of solvation. It is a particular special case of water. [1] The value of hydration energies is one of the most challenging aspects of structural prediction. [2] Upon dissolving a salt in water, the cations and anions interact with the positive and negative dipoles of the water.
Once dissolved, distribution of the dissolved gas is by perfusion, where the solvent (blood) is circulated around the diver's body, and by diffusion, where dissolved gas can spread to local regions of lower concentration when there is no bulk flow of the solvent. Given sufficient time at a specific partial pressure in the breathing gas, the ...
Free nitrogen atoms easily react with most elements to form nitrides, and even when two free nitrogen atoms collide to produce an excited N 2 molecule, they may release so much energy on collision with even such stable molecules as carbon dioxide and water to cause homolytic fission into radicals such as CO and O or OH and H. Atomic nitrogen is ...
The self-diffusion coefficient of neat water is: 2.299·10 −9 m 2 ·s −1 at 25 °C and 1.261·10 −9 m 2 ·s −1 at 4 °C. [2] Chemical diffusion occurs in a presence of concentration (or chemical potential) gradient and it results in net transport of mass. This is the process described by the diffusion equation.
If water molecules become suspended among the substance's molecules, adsorbing substances can become physically changed, e.g. changing in volume, boiling point, viscosity or some other physical characteristic or property of the substance. For example, a finely dispersed hygroscopic powder, such as a salt, may become clumpy over time due to ...
Hydrolysis (/ h aɪ ˈ d r ɒ l ɪ s ɪ s /; from Ancient Greek hydro- 'water' and lysis 'to unbind') is any chemical reaction in which a molecule of water breaks one or more chemical bonds. The term is used broadly for substitution , elimination , and solvation reactions in which water is the nucleophile .