GENERAL KNOWLEDGE

Detailed explanation-1: -Heavy, stubborn rust stains can often be removed by applying oxalic acid stain remover compounds such as Zud or a trichloro-melamine compound such as Barkeeper’s Friend.

Detailed explanation-2: -To remove rust stains from clothes, mix a few drops of hydrogen peroxide together with a teaspoon of tartar cream and baking soda. Apply the resulting paste onto the stain, let it sit for 30 minutes, then rinse it thoroughly and wash the clothes as usual.

Detailed explanation-3: -Oxalic acid is widely used as an acid rinse in laundries, where it is effective in removing rust and ink stains because it converts most insoluble iron compounds into a soluble complex ion.