Abstract:

Potassium tris(oxalato) ferrate(Ⅲ) trihydrate has the industrial production value, and its synthesis is a classic experiment in the laboratory course for chemistry majors. However, results from the experimental procedure in the textbook are unsatisfactory. Based on the rigorous analysis of chemical equilibrium theory, we first proposed that the key factor for improving the yield is to strictly control the amount of oxalic acid and potassium oxalate. The improved synthesis conditions are as follows:in the oxidation step, the reaction is carried out at 40℃, and the concentration of H₂O₂ is 6%; after full oxidation, the solution is kept boiling for two minutes; a slight excess of oxalic acid and 10% excess of potassium oxalate are used in the acid dissolution step; sufficiently cooling is followed in crystallization. With the improved procedure, operations are simplified and raw materials are saved. The yield is 87% for laboratory average and greater than 70% for students in the laboratory class.

Key words: Potassium tris(oxalato) ferrate(Ⅲ) trihydrate, Complex, Synthesis, Chemical equilibrium