In order for CrO42- to serve in this capacity, the solubility of Ag2CrO4(s) must be sufficiently greater than that of Ag2CrO4(s) are formed. This means that the effective solubility product (Ksp) of Ag2CrO4(s) must be slightly greater than that of AgCl. Since indicators of this kind require an excess of reagent to form enough colored precipitate for visual detection, determination of this excess, commonly referred to indicator error or blank, must be made and applied to all titrations.