Correct Option: C

Oxalic acid is an organic compound with the formula H2C2O2. It is a colourless crystalline solid that dissolves in water to give colourless solutions. It is classified as a dicarboxylic acid. In terms of acid strength, it is much stronger than acetic acid. Oxalic acid is a reducing agent and its conjugate base, known as oxalate , is a chelating agent for metal cations. Typically, oxalic acid occurs as the dihydrate . Ingestion of oxalic acid through skin contact or orally is dangerous. Oxalic acid’s main applications include cleaning or bleaching, especially for the removal of rust, e.g. Bar Keepers Friend is an example of a household cleaner containing oxalic acid. About 25% of produced oxalic acid is used as a mordant in dyeing processes. It is used in bleaches, especially for pulpwood. It is also used in baking powder.