Carboxylate Ion Attack

When acids come into contact with concrete, they initiate a chemical reaction that dissolves the hydrated cement paste. This process leads to softening and structural weakening of the concrete. This issue is commonly observed in environments such as chimneys, sewers, and industrial settings. The severity of the damage increases as the pH of the water interacting with the concrete drops below 6.5. In particular, a pH under 4.5 can cause significant concrete damage. The rate at which hydrogen...

In competitive marketing, companies strategically decide which competitors to challenge or avoid based on market share, product offerings, and operational efficiency. Attacking a competitor involves identifying exploitable weaknesses, such as poor customer service, outdated products, or inefficient processes. Smaller companies often successfully challenge larger firms by leveraging their agility, offering more responsive customer support or faster innovation cycles. For example, ride-sharing...

Source: Laboratory of Dr. B. Jill Venton - University of Virginia Ion-exchange chromatography is a type of chromatography that separates analytes based on charge. A column is used that is filled with a charged stationary phase on a solid support, called an ion-exchange resin. Strong cation-exchange chromatography preferentially separates out cations by using a negatively-charged resin while strong anion-exchange chromatography preferentially selects out anions by using a positively-charged...

Sulfate attack on concrete is a deterioration process characterized by a whitish discoloration beginning at the edges and corners, accompanied by cracking and spalling. This phenomenon occurs when sulfates react with the components of hardened concrete, forming compounds like calcium sulfate and calcium sulfoaluminate which occupy more space than the substances they replace, causing the concrete to expand and disrupt. Sulfates from sources like soil, groundwater, or industrial effluents...

Compared with pure water, the solubility of an ionic compound is less in aqueous solutions containing a common ion (one also produced by dissolution of the ionic compound). This is an example of a phenomenon known as the common ion effect, which is a consequence of the law of mass action that may be explained using Le Châtelier’s principle. Consider the dissolution of silver iodide: This solubility equilibrium may be shifted left by the addition of either silver(I) or iodide ions, resulting in...