Stains of rust on cloths can be removed by

Correct option is A

Oxalic acid is used to remove rust stains from clothes due to its chemical reaction with iron oxide.

Explanation:
● Oxalic acid reacts with iron oxide (rust) to form a water-soluble compound, which can be washed away.
● It is commonly used in cleaning agents and rust removers.
● Oxalic acid must be diluted before application to prevent fabric damage.
● Natural alternatives like lemon juice and vinegar also contain mild acids effective against rust stains.
● Industrial cleaning often uses oxalic acid for metal surface treatment.
● Proper handling is essential, as oxalic acid is corrosive and toxic in concentrated forms.

Information Booster:
● Rust forms due to the reaction of iron with oxygen and moisture, creating iron oxide.
● Oxalic acid is found naturally in foods like spinach and rhubarb.
● It is widely used in industries, including textiles, metal cleaning, and bleaching.
● Acids neutralize rust by breaking down its chemical bonds.
● Always rinse thoroughly after treating fabrics with oxalic acid to avoid residue.

Additional Information:

• (B) Petrol: Ineffective against rust stains.
• (C) Alcohol: Does not react with iron oxide.
• (D) Hydrogen Peroxide: A bleaching agent but not effective on rust.