As per Hume-Rothery rules of solid solubility, the difference bet

SOLUTION

Explanation:

Solid Solution

• Solid solution or an alloy is a phase where two or more elements are completely soluble in each other.
• Solid solution have important commercial and industrial applications, as such mixture have superior properties to pure materials.
• Many metal alloys are solid solutions such as Cu-Ni, Au-Ag etc.
• In a solid solution, the metal in the major proportion is called the solvent (host / parent / matrix) and the metal in the minor proportion is called solute.

There are two types of solid solutions.

• Substitutional solid solution.
• Interstitial solid solution.

Hume-Rothary Rule:

These are the rules which governed the formation of solid solutions i.e. only when these rules are satisfied a substitutional solid solution is formed.

Crystal Structure Factor:

• For complete solubility of two elements, they should have the same type of crystal lattice.
• For eg. Au-Ag solution, both should have FCC structure.

Relative Size Factor:

• The atoms of the solute and solvent should have the same atomic size approximately.
• The factor is satisfied if the difference of the atomic radii of two element is less than 15 %.

Chemical Affinity Factor:

• Two metal should have less chemical affinity.
• Greater the chemical affinity, lesser the chance of forming solid solution.
• Chemical affinity is more if two element is farther apart in periodic table.

Electro-negativity:

• Higher the electro-negativity, greater is the chance of forming an intermediate phase rather than a solid solution.
• Electro-negativity is the tendency to acquire electrons.

Relative Valence Factor:

• Among two metals, which have satisfied all the above rules, the metal with lower valency tends to dissolve more of a metal of higher valency and vice-versa.