Question

Hydrogen peroxide helps in the restoration of old lead paintings.

Explain the chemistry behind it.

Answer 1

HEY FOLK...

H2O2 helps for restoring colour of old lead paintings.

What actually happens is lead paintings have white lead whose white lead has
blackened due to formation of PbS by H2S of atmosphere.

And with the help of hydrogen peroxide  the black lead sulphide can be converted to white lead sulphate.

reaction involved is:  PbO(white)  + H2S ------> PbS(black) + H2O


Since, H2O2 is strong oxidising agent, and when painting is dipped in solution of H2O2 , PbS slowly oxidises to white lead sulfate

PbS + 4H2O2 --------> PbSO4 + 4H2O




HOPE IT HELPS...

#Mme