Unit – II D

Solid Solutions:

Solid Solutions (Alloys):

  • A solid solution of two or more metals or metal or metals with one or more non-metal is called an alloy.
  • Primarily there are two types of solid solutions


    Solute atoms occupy the regular lattice sites of the parent metal (solvent). Substitutional solid solutions can be random (Cu-Ni) or ordered (Cu-Au).


    Solute atoms occupy the interstitial positions (Steel – C solute atoms in Fe) .

Examples of Alloys:


  • Composition: Aluminum, copper, manganese, magnesium.
  • Uses: aircraft, boats, railroad cars, and machinery because of its high strength and resistance to corrosion

Aluminium bronze:

  • Composition: Aluminum, copper, manganese
  • Uses: heavy duty sleeve bearings, and machine tool ways. Aluminum bronze castings have exceptional corrosion resistance, high strength, toughness and wear resistance and good casting and welding characteristics.

Hardened Lead:

  • Composition:10 to 20 % antimony
  • Uses: bearings, bullets and shrapnel

Stainless Steel:

  • Composition: Iron, chromium, nickel
  • Uses: Cutlery, surgical instruments, utensils


  • Composition: Iron and 5 to 20 % manganese
  • Uses: Very hard hence used for making rails, safes and heavy machinery.


  • Composition: Iron and 70 to 80 % manganese
  • Uses: Very hard hence used for making rails, safes and heavy machinery.


  • Composition: I84 % Cu, 12 % Mn, 4% Ni
  • Uses: electrical measurement instrument due to zero temperature coefficient of resistance.


  • Alloys of mercury with other metals are called amalgams.
  • This property of mercury is used for extraction of metals like silver and gold from their ores. These metals are further recovered by distillation of mercury.


  1. What is the concentration of dissolved oxygen at 25 °C at 1-atmosphere pressure if the partial pressure of oxygen is 0.22 atm? The henry’s law constant for oxygen is 1.3 × 10-5 mol dm-3 atm-1.
  2. The solubility of nitrogen gas at 1 atm pressure at 25 °C is 6.8 × 10-4 mol dm-3. Calculate the solubility of N2 gas from the atmosphere at 25 °C if the atmospheric pressure is 1 atmosphere and partial pressure of N2 gas at this temperature and pressure is 0.78 atm.

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