adsorption isotherm An equation that describes how the amount of a substance adsorbed onto a surface depends on its pressure (if a gas) or its concentration (if in a solution), at a constant temperature. Several adsorption isotherms are used in surface chemistry including the BET isotherm and the Langmuir adsorption isotherm. The different isotherms correspond
adsorption indicator (absorption indicator) A type of indicator used in reactions that involve precipitation. The yellow dye fluorescein is a common example, used for the reaction NaCl(aq) + AgNO3(aq) → AgCl(s) + NaNO3(aq) As silver nitrate solution is added to the sodium chloride, silver chloride precipitates. As long as Cl” ions are in excess, they