The valency of lead (Pb) is variable, meaning it can show more than one valency depending on the compound.
Common valencies of lead:
- +2 (Pb²⁺) → called plumbous
- +4 (Pb⁴⁺) → called plumbic
Which is more stable?
- +2 valency (Pb²⁺) is more stable than +4
- This is due to the inert pair effect, where the outermost s-electrons are less likely to participate in bonding
Examples:
- PbCl₂ → Lead (II) chloride
- PbO → Lead (II) oxide
- PbCl₄ → Lead (IV) chloride
Key Takeaway:
Lead commonly shows +2 and +4 valencies, with +2 being more stable and more frequently observed.