Hydrogen

JEE Main 2015 Discussion Forum › Inorganic Chemistry questions › Hydrogen

Statues coated with white lead on long exposure to atmosphere turn black and the original colour can be restored on treatment with H₂O₂ .Why ?

#Chemistry #Inorganic Chemistry

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5 Answers

1

Arka Halder ·2009-12-17 02:16:01

Due to reaction with atmospheric H₂S gas,PbS is formed which is black.
On treatment with H₂O₂,the black PbS is oxidised to PbSO₄ which is white,thus restoring original colour.
PbS + 4H₂O₂ â†’ PbSO₄ + 4H₂O.
This is also the same reason as to why old oil paintings are washed in a solution of H₂O₂ to restore their original colour.

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11

Gone.. ·2009-12-17 04:57:35

agree wid arka.

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1

Jagaran Chowdhury ·2009-12-18 03:52:31

PbS+4[o=PbSO₄

{H₂O₂=H₂O+[O]}*4
______________________________________
PbS+4H₂O₂=PbSO₄+4H₂O

this is the complete reaction

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Jagaran Chowdhury ·2009-12-18 03:53:48

is there any problem with this site??what r these lines... i ddnt make them

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mentor_Layak Singh ·2009-12-18 07:03:14

yes ..answer is correct !!!!!!!

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