These salts feature well separated MeN cations and hydroxide anions. It is a white solid ionic compound consisting of sodium cations and hydroxide anions . The dissolved electrolyte separates into cations and anions, which disperse uniformly through the solvent. Water ionizes into hydronium (HO) cations and hydroxide (OH) anions. Most fluids contain ions, positive (cations) and negative (anions). Salts of quaternary ammonium cations are known. There are also amphoteric exchangers that are able to exchange both cations and anions simultaneously. The solid contains separate sodium cations and glutamate anions in zwitterionic form, OOC-CH()-()-COO. KMnO is a salt, consisting of K cations and MnO anions. Salts exist in many different colors, which arise either from the anions or cations. Conductivity is usually about 100 times the total cations or anions expressed as equivalents. Ionophores selective for cations and anions have found many applications in analysis. The citrate ion forms complexes with metallic cations. Xanthates bind to transition metal cations as bidentate ligands. Lead(II) sulfate is insoluble in water, like the sulfates of other heavy divalent cations.