Question

When red lead is treated with $HCl$ , the product obtained is:
A. $C{l_2}$
B. ${O_2}$
C. ${H_2}$
D. None of these.

Answer 1

Hint: Red lead is a compound of lead that is red in colour due to the presence of oxygen atoms. The molecular formula of Red Lead is $P{b_3}{O_4}$ . It undergoes a redox reaction when it is treated with $HCl$ .

Complete step by step answer:
Red lead is a compound formed from lead belonging to the d block. It is acidic in nature since lead usually exhibits $ + 2$ oxidation state. It has anti rusting properties.
Therefore, the reaction of red lead with hydrochloric acid is demonstrated below:
$P{b_3}{O_4} + HCl \to PbC{l_2} + {H_2}O + C{l_2}$
We can see that red lead is undergoing reduction after reacting with hydrochloric acid. The chlorine in the hydrochloric acid undergoes oxidation. The oxidation number change in the Lead is $ + \dfrac{8}{3} \to + 2$ that is lead acts as an oxidising agent. The number change for chlorine is $ + 1 \to 0$ . This means that the chlorine acts as a reducing agent.
But it is also important to write the balanced equation.
When we look at the equation we see that, $3$ atoms of lead are present in the reactant side and there is only one atom on the product side.
Therefore, we will $3$ molecules of Lead chloride to the product side. Therefore, the reaction will now be:
$P{b_3}{O_4} + HCl \to 3PbC{l_2} + {H_2}O + C{l_2}$
But now the chlorine atoms on the product side are more. Therefore, we will consider $8HCl$ on the reactant side.
The reaction will now be:
$P{b_3}{O_4} + 8HCl \to 3PbC{l_2} + {H_2}O + C{l_2}$
Now the lead atoms and the chlorine atoms are balanced. But the hydrogen and oxygen atoms are not.
Therefore, we will now consider $4{H_2}O$ to the product side. The reaction will now be:
$P{b_3}{O_4} + 8HCl \to 3PbC{l_2} + 4{H_2}O + C{l_2}$
Therefore, now all the atoms are balanced.

So, the correct answer is Option A.

Note: The gas released when lead oxide reacts with hydrochloric acid is chlorine. Lead will be the oxidising agent and hydrochloric acid is the reducing agent.
Red lead has acidic character and also forms Lead chloride in the above reaction.