As a model of the new system a prototype allows for several forms of communication. First, it allows the developers to communicate to the users their understanding of the requirements. (Obviously before a prototype can be built there must be some initial requirements discussions between developers and users).
(Arrhenius) a substance that yeilds hydroxide ions in an aqueous solution; metallic oxides in water. Buffers. substances that in solution are capable of neutralizing, within limits both acids and bases, and thereby maintaining the original or constant pH of the solution; substances that prevent changes in pH. Ex. borax, sodium phosphates, and citrates. Crystallization. the process by which a substance is given definite form.
Acids are primary contributors to the measure of pH in a solution, and the presence of acids a key characteristic of almost all solutions, from blood in the body to foods and drinks we consume. Let's discuss what an acid is and how it affects the pH of solutions when added. How Acids Work. The pH scale is a scale that is used to represent the level of acidity in a solution. A solution with a pH of 7 is neutral, while a solution with a pH below 7 is an acid, and a solution with a pH above 7 is a base. An acid dissociates, or breaks apart, and donates protons, or hydrogen ions, in an aqueous solution, while a base donates hydroxide ions in a solution. Water, for example, is neutral with a pH of 7.