Q. Assertion : Third law of thermodynamics is confined to pure crystalline solids.
Reason : Theoretical arguments and practical evidences have shown that entropy of solutions and super cooled liquids is not zero at .

 1460  203 Thermodynamics Report Error

Solution:

According to the third law of thermodynamics, "The entropy of a perfectly crystalline substance at zero K or absolute zero is taken to be zero". So according to the statement , both assertion and reason are correct and the reason is the correct explanation of assertion