Question

When exposed to air containing hydrogen sulfide, lead-based paints turn black because the Pb2+ ions react with the H2S to form black lead sulfide (PbS). This has caused the darkening of old oil-based paintings. Hydrogen peroxide lightens the paints by oxidizing the black sulfide (S2−) to white sulfates (SO2−4).

Write the equation for this reaction that lightens the paints.

Answer 1

The equation for the reaction that lightens the paints is PbS(s) + 4H+(aq) + O2(g) → PbSO4(s) + 2H2O(1).

Step-by-step explanation:

An equation for the reaction that lightens the paints is:

PbS(s) + 4H+(aq) + O2(g) → PbSO4(s) + 2H2O(1)

In this reaction, hydrogen peroxide (H2O2) acts as an oxidizing agent. It oxidizes the black lead sulfide (PbS) to white lead sulfate (PbSO4). The hydrogen peroxide is reduced to water in the process. This reaction is an example of a redox reaction.