Answer:
When the old oil paintings are kept in the
atmosphere for a long period, the traces of \[{{H}_{2}}S\] gas present in the atmosphere
converts lead oxide (PbO) into lead sulphide (PbS) which is black in colour.
Therefore, these paintings get tarnished. The original whiteness can be
restored by keeping them in hydrogen peroxide solution for sometime as a result
of which lead sulphide is oxidised to lead sulphate.
\[\underset{\text{(Black)}}{\mathop{PbS}}\,+4{{H}_{2}}{{O}_{2}}\xrightarrow{\,}\,\underset{\text{(White)}}{\mathop{PbS{{O}_{4}}}}\,+4{{H}_{2}}O\]
You need to login to perform this action.
You will be redirected in
3 sec
