The most commonly used bleaching agent is chlorine. It is a powerful oxidizer that can break down the bonds that hold color molecules together, causing them to lose their color. Chlorine is used in a variety of bleaching products, including household bleach, laundry detergent, and swimming pool chemicals.
Alcohol is not a bleaching agent. It is a solvent that can be used to remove stains, but it does not have the ability to bleach colors.
Carbon dioxide is a gas that is not a bleaching agent. It is used in some industrial bleaching processes, but it is not commonly used in household products.
Sodium chloride is table salt. It is not a bleaching agent. It can be used to remove stains, but it does not have the ability to bleach colors.
Chlorine is the most commonly used bleaching agent because it is effective, inexpensive, and readily available. It is important to use chlorine bleach safely, as it can be harmful if inhaled or ingested.