Chemistry - Lead

Introduction

• Lead is a heavy chemical element (metal) i.e. it has high density.

• The symbol of lead is ‘Pb’ and atomic number is ‘82.’

• Lead has tendency to bond itself; likewise, it can form chains, bonds, rings, and polyhedral structures.

Salient Features of Lead

• Lead is soft and malleable metal; it has relatively low melting point.

• Lead is relatively unreactive element and it has tendency to form covenant bond.

• When lead is cut, it appears bluish-white tint.

• While burning, lead gives a bluish-white flame (see the image given below).

• Compounds of lead are typically found in the +2 oxidation state.

Occurrence of Lead

• Lead is known to the prehistoric people of Western Asia.

• Lead is found in the earth’s crust; it is rarely found deep of the earth.

• Lead is usually found in combination with sulfur.

• Galena is the main lead-bearing mineral, mostly found with zinc ores.

Alloys of Lead

• Following are the major alloys of lead −

  • Molybdochalkos (copper)

  • Solder (tin)

  • Terne (tin)

Compounds of Lead

• Following are the major compounds of lead −

  • Lead monoxide - PbO

  • Lead dioxide - PbO₂

Uses of Lead

• Lead has been used in making bullets for hundreds of years.

• Lead is commonly used as a protective sheath for the underwater cables (only because it has the property of corrosion resistance).

• Lead sheets are also used as architectural metals especially in roofing material.

• Lead is also used in acid batteries.

• Lead compounds are commonly as coloring agents and semiconductors.

• Lead compounds are also used in plastic, candles, glass, etc.

• Lead is commonly used in the polyvinyl chloride (i.e. used in coating of electrical cords).

Pre-caution

• Presence of lead (in excessive quality) in the body may cause severe damage to the brain and kidneys; it may even cause death lastly.