What is "sodium oxalate"

Sodium oxalate, or disodium oxalate, is the sodium salt of oxalic acid with the formula NaCO. It is usually a white, crystalline, odorless powder, that decomposes at 250–270 °C.

Disodium oxalate can act as a reducing agent, and it may be used as a primary standard for standardizing potassium permanganate (KMnO) solutions.

The mineral form of sodium oxalate is natroxalate. It is only very rarely found and restricted to extremely sodic conditions of ultra-alkaline pegmatites.