Copper (II) reacts with citric acid and a neutral complex, C, is formed at lower \(p\)H. The ligand occupies three-co-ordination position and the fourth co-ordination position of copper is most probably oceupied by a molecule of water. The result obtained by \(p\)H titrations indicate the complex C to be a dibasic acid. dissociating successively in two steps to C1- and C22- Conductometric titration of a mixture of citric acid and copper nitrate against standard sodium hydroxide solution

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... ively supports the above results obtained by \(p\)H titration. The equilibrium constant of the reaction of the formation of C from Cu2+ and citric acid with the liberation of two protons and those of the reactions (i) C \( \rightleftharpoons\) C1- \(+\) H+ and (ii) C1- \( \rightleftharpoons\) C22- \(+\) H+ have been determined. The probable structures of the complex have been discussed.