how does the iron (III) chloride test work?
<answer> When dissolved in water, iron(III) chloride undergoes hydrolysis and gives off heat in an exothermic reaction. <context> When dissolved in water, iron(III) chloride undergoes hydrolysis and gives off heat in an exothermic reaction. The resulting brown, acidic, and corrosive solution is used as a flocculant in sewage treatment and drinking water production, and as an etchant for copper-based metals in printed circuit boards.ron(III) chloride hexahydrate consists of trans -[Fe(H 2 O) 4 Cl 2 ] + cationic complexes and chloride anions, with the remaining two H 2 O molecules embedded within the monoclinic crystal structure. Iron(III) chloride has a relatively low melting point and boils at around 315 °C.