Oxalic acid, chemically represented as H2C2O4, is a white, crystalline powder or granule that is also referred to as thanedioic acid. It is a straightforward dibasic acid with a sour taste that dissolves readily in ethanol and water, dissolves somewhat in ether, and is insoluble in benzene. The oxalic acid crystal will become anhydrous oxalic acid and lose its crystal water content when heated to 100°C. The translucent, odourless, colourless crystal or white powder known as anhydrous oxalic acid is toxic and soluble in ether, alcohol, and water. Furthermore, oxalic acid dihydrate is a colourless crystal that, when heated or exposed to dry air, will lose moisture and turn into a white powder.

In nature, oxalic acid is found in abundance and is frequently found in different plants as oxalate, such as the cell