When a strong acid (e.g., HCl) is placed in water, the acid ionizes completely as: $$ HCl+H_2O→H^++Cl^- $$ Three species are present in the aqueous solution of the strong acid: H+, OH–, and Cl–. H+, generated from HCl, suppresses the ionization of H2O. This leads to the lower concentration of H+ in water than the […]
The hydrogen ion concentration of a solution varies from approximately 1 in a 1 M solution of a strong acid to about 1×10-14 in a 1 M solution of a strong base, and the calculations often become unwieldy. To alleviate this difficulty, Sörensen suggested a simplified method of expressing hydrogen ion concentration. He established the […]
The concentration of hydrogen or hydroxyl ions in solutions of acids or bases may be expressed as gram-ions per liter or as moles per liter. A solution containing 17.008 g of hydroxyl ions or 1.008 g of hydrogen ions per liter is said to contain 1 gram-ion or 1 mole of hydroxyl or hydrogen ions […]
A weak base is one that, when dissolved in water, only partially dissociates. As a result, the aqueous solution contains a relatively small amount of hydroxide ions and the corresponding base ions, while most of the base remains in its undissociated molecular form. Common examples of weak bases include ammonia (NH3), baking soda (sodium bicarbonate, […]
Weak acids are acids that do not completely dissociate into their ions when dissolved in water. Instead, they partially ionize, meaning only a fraction of the acid molecules release hydrogen ions (H+) into the solution. The rest of the molecules remain in their undissociated form. This creates an equilibrium between the undissociated acid and its […]
Theories of acids and bases have evolved over time to explain their chemical behavior and interactions in various contexts. The most prominent theories include Arrhenius, Brønsted-Lowry, and Lewis theories. Each theory builds upon its predecessors, providing deeper insight into the nature of acids and bases. Below is an introduction to these major theories: Arrhenius Theory […]
The formulation of suspensions possessing optimal physical stability depends on whether the particles in suspension are to be flocculated or to remain deflocculated. One approach involves the use of a structured vehicle to keep deflocculated particles in suspension. A second approach depends on controlled flocculation as a means of preventing cake formation. A third, a […]
A pharmaceutical suspension is a coarse dispersion in which insoluble solid particles are dispersed in a liquid medium. The particles typically have diameters greater than 0.1 μm. Under a microscope, some of these particles can exhibit Brownian movement if the dispersion has low viscosity.[1] Interfacial Properties of Suspension Because suspensions are dispersions of one phase […]
Cyclodextrin (CD) is a group of compounds known as cyclic oligosaccharides. They consist of at least six D-(+)-glucopyranose units linked together by α-1,4 bonds, and are produced through the enzymatic action of Bacillus macerans amylase on starch.[1] Types and Properties of Cyclodextrin Cyclodextrins consist of 6, 7, and 8 units of glucose referred to as […]
Occlusion or inclusion complexes results more from the architecture of molecules than from their chemical affinity. One of the constituents of the complex is trapped in the open lattice or cage-like crystal structure of the other to yield a stable arrangement. Channel Lattice Type In this complex, the host component crystallizes to form a channel-like […]