What do you observe when:

When lead monoxide is heated in a charcoal.

• Lead monoxide when heated in a charcoal cavity leaves a shining globule behind.
• This is because charcoal acts as a reducing agent and reacts with lead monoxide to form a shining globule of lead and carbon monoxide gas.

$\mathrm{PbO}\left(\mathrm{s}\right)+\mathrm{C}\left(\mathrm{s}\right)\to \mathrm{Pb}\left(\mathrm{s}\right)+\mathrm{CO}\left(\mathrm{g}\right)$

(Shinning globule)

Concluding Statement: When lead monoxide is heated in a charcoal - red mercury oxide turns to shinning globule)