Question

Why is hydrogen peroxide kept in coloured bottles?

Answer 1

Hint: Hydrogen peroxide is a highly reactive chemical. It is highly unstable and slowly decomposes when kept in presence of light. Due to this reason, hydrogen peroxide should be kept in amber coloured bottles or in opaque bottles so that little or no light passes through it.

Complete step by step answer:
Hydrogen peroxide is the highly reactive chemical compound with molecular formula 34. In pure form, it is a very pale blue coloured liquid and slightly more viscous in nature than water.
Decomposition reaction of hydrogen peroxide is:
$2{H_2}{O_2} \to 2{H_2}O + {O_2}$
It is decomposing into water and oxygen in presence of light. Due to its instability, it is typically stored with a stabilizer in a weakly acidic solution in an amber(dark) coloured bottle. Hydrogen peroxide is a strong oxidizing agent in various industries. It is having biological function as an antioxidant and present in human beings. It is used as a bleaching agent in pulp and paper bleaching.

Note:
Hydrogen peroxide is having wide application from the bleaching industry to the medical field. In the bleaching industry, it is used as a bleaching agent while in the medical field, the mild hydrogen peroxide is safe as an antimicrobial agent and thus used as an antiseptic. It is also used as a disinfectant to remove organic impurities in waste-water treatment plants. Concentrated hydrogen peroxide or high-test peroxide is a reactive oxygen species (ROS) which is used as a propellant in rocketry. Nowadays, it is manufactured exclusively by the anthraquinone process with the palladium as a catalyst. The mixture of sulfuric acid, hydrogen peroxide and water are called as piranha solution or piranha etch which is used to clean organic residues.