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When the dissolution rate of a pure substance is normalized to the surface area of the solid (which usually changes with time during the dissolution process), then it is expressed in kg/m 2 s and referred to as "intrinsic dissolution rate". The intrinsic dissolution rate is defined by the United States Pharmacopeia. Dissolution rates vary by ...
Solvation or dissolution is a kinetic process and is quantified by its rate. Solubility quantifies the dynamic equilibrium state achieved when the rate of dissolution equals the rate of precipitation. The consideration of the units makes the distinction clearer. The typical unit for dissolution rate is mol/s.
A solubility equilibrium exists when a chemical compound in the solid state is in chemical equilibrium with a solution containing the compound. This type of equilibrium is an example of dynamic equilibrium in that some individual molecules migrate between the solid and solution phases such that the rates of dissolution and precipitation are equal to one another.
An example where Henry's law is at play is the depth-dependent dissolution of oxygen and nitrogen in the blood of underwater divers that changes during decompression, going to decompression sickness. An everyday example is carbonated soft drinks, which contain dissolved carbon dioxide.
Substance A and B are somewhat homogenous in a system prior to the introduction of substance C. [10] At the beginning of the leaching process, substance C will work at dissolving the surficial substance B at a fairly high rate. [1] The rate of dissolution will decrease substantially once it needs to penetrate through the pores of substance A in ...
A weak electrolyte is a substance whose solute exists in solution mostly in the form of molecules (which are said to be "undissociated"), with only a small fraction in the form of ions. Simply because a substance does not readily dissolve does not make it a weak electrolyte. Acetic acid (CH 3 COOH) and ammonium (NH + 4) are good examples ...
There are three typical situations where dissolution testing plays a vital role: (i) formulation and optimization decisions: during product development, for products where dissolution performance is a critical quality attribute, both the product formulation and the manufacturing process are optimized based on achieving specific dissolution targets.
Dissolution (also called simple solution or congruent dissolution) is the process in which a mineral dissolves completely without producing any new solid substance. [24] Rainwater easily dissolves soluble minerals, such as halite or gypsum, but can also dissolve highly resistant minerals such as quartz, given sufficient time. [25]