Question

The ${H_2}{O_2}$ on reaction with $PbS$ gives:
(A) $PbO$
(B) $PbS{O_4}$
(C) $Pb{O_2}$
(D) $PbHS{O_4}$

Answer 1

To solve this question we should always learn the properties of the hydrogen peroxide.Hydrogen peroxide has oxidizing and reducing nature. It behaves as an oxidising as well as reducing agent in the both acidic and alkaline mediums.it is a powerful oxidising agent but a weak reducing agent.

Complete step-by-step answer: As in the given question we have to give the product of the following reactant:
${H_2}{O_2}$ and $PbS$
On mixing the both reactants we get some output from the reaction.
We all know that aqueous solution of hydrogen peroxide oxidises the lead sulphide into lead sulphate
As in the given below reaction we can see:
${H_2}{O_2} \to {H_2}O + [O]$
From the above given reaction we can say that hydrogen peroxide gives one nascent oxygen.
Now this nascent oxygen will oxidise the lead sulphide.
We can see the oxidation of the lead sulphide as given below:
$PbS + 4[O] \to PbS{O_4}$
Now we will combine the both reactions to give the product of the given reactant .
Hence,
$[{H_2}{O_2} \to {H_2}O + [O]]$ $\times 4$
$PbS + 4[O] \to PbS{O_4}$
Now overall reaction will be:
$PbS + 4{H_2}{O_2} \to PbS{O_4} + 4{H_2}O$

So, after getting the product from the reaction we can say that the on reacting hydrogen peroxide with lead sulphide we get the a white product of the lead sulphate.
This reaction is used for restoration of white colour to lead paintings which have been blackened due to ${H_2}S$ present in the atmosphere.

Note: Properties of ${H_2}{O_2}$:
I. Pure anhydrous hydrogen peroxide is a syrupy liquid. It is colourless but gives a bluish tinge in thick layers. It is odourless.
II. Its specific gravity is 1.45 at ${0^0}C$ and more viscous than water. This is due to the fact that molecules of ${H_2}{O_2}$are more associated through H-bonding.
III. It is soluble in water, alcohol, and ether in all proportions.
IV. It has a bitter taste. It is injurious to skin.