Why is hydrogen peroxide kept in coloured bottles?

Hydrogen Peroxide (H₂O₂) is a highly reactive chemical compound with a molecular mass of 34. In its pure form, it appears as a very pale blue liquid and is slightly more viscous than water.

Decomposition of Hydrogen Peroxide

Hydrogen peroxide readily decomposes into water and oxygen in the presence of light:

2H₂O₂ → 2H₂O + O₂

Because of its instability, it is usually stored with a stabilizer in a weakly acidic solution inside amber-colored bottles to prevent decomposition.

Properties and Uses

• Oxidizing Agent: Hydrogen peroxide is a strong oxidizing agent widely used across different industries.
• Biological Role: It also functions as an antioxidant in biological systems and is naturally present in humans.
• Bleaching Agent: Commonly used in pulp and paper industries for bleaching purposes.

Applications

• Industrial Uses: In the bleaching industry, it serves as an effective bleaching agent.
• Medical Field: Mild hydrogen peroxide solutions act as safe antimicrobial agents, making them useful as antiseptics and disinfectants.
• Wastewater Treatment: It helps remove organic impurities in treatment plants.
• Rocketry: Concentrated hydrogen peroxide (high-test peroxide), a reactive oxygen species (ROS), is used as a propellant.
• Manufacturing: Today, hydrogen peroxide is produced mainly through the anthraquinone process using palladium as a catalyst.
• Special Solutions: A mixture of sulfuric acid, hydrogen peroxide, and water forms piranha solution (piranha etch), used to clean organic residues.