Potassium tetraoxalate preparation [closed]

Question

How is potassium tetraoxalate produced industrially? In fact How I can limit the reaction of $\ce{H2C2O4}$ and $\ce{KOH}$?

Or is there any other route for this purpose?

Answer 1

In fact How I can limit the reaction of H2C2O4 and KOH?

If you are to react potassium hydroxide with oxalic acid in 1:1 mole ratio, you will get potassium hydrogenoxalate ($\ce{KHC2O4}$). Its hydrate form exist at a specific temperature range. This salt contains the hydrogenoxalate anion and hence known as acid potassium oxalate. But if you add an excess of concentrated oxalic acid and maintaining a temperature of below $\pu{50 °C}$, the much less soluble potassium tetraoxalate ($\ce{K+[C2HO4]^−.C2H2O4}$) forms and precipitates out of solution since it is sparingly soluble in water. So your target compound depends on the concentration of the reagents and the temperature.

Or is there any other route for this purpose?

There is a patent which claims to have made potassium oxalate from potassium formate.