Question

Hydrogen peroxide is used to restore the colour of old oil paintings containing feed oxide. Write a balanced equation of the reaction that takes place in this process.

Answer 1

Hint: We must also know that the chemical formula of hydrogen peroxide is \[{{\text{H}}_{\text{2}}}{{\text{O}}_{\text{2}}}\]. The hydrogen peroxide is a light sensitive reagent. It is in colourless liquid form. It is moisture sensitive also. If we open for some time oxygen will escape and form water.

Complete answer:
We must have to know that the hydrogen peroxide is used to restore the colour of old oil paintings containing feed oxide.
In painting using lead, after some years it forms lead sulphide. Because of this forming lead sulphide the decolourisation will happen. This contains some feed oxide nature. Once coating with hydrogen peroxide, it oxidised lead sulphide to form lead sulphate. The colour of the painting will retain it.
Balanced chemical of the above discussion reaction is
\[{\text{PbS + 4}}{{\text{H}}_{\text{2}}}{{\text{O}}_{\text{2}}} \to {\text{PbS}}{{\text{O}}_{\text{4}}}{\text{ + 4}}{{\text{H}}_{\text{2}}}{\text{O}}\]

Note:
We have to remember that the hydrogen peroxide is used as one of the oxidising agents. It is a strong oxidising agent reaction-wise. Hydrogen peroxide is also a reducing agent. Usually hydrogen peroxide acts as an oxidising agent in acidic medium and acts as reducing agent in basic medium. The reactivity of hydrogen peroxide is dependent on the pH of the reaction. If the pH of the reaction is less than seven means that is an acidic medium. If the pH value is greater than seven means that is the basic medium. The oxidation means the addition of oxygen or removal of hydrogen or the loss of electrons in the reactant. The reduction means the removal of hydrogen or the addition of oxygen or the gain of electrons in the reaction. It is a highly unstable reagent.