Engineering Metallurgy - Mechanical Engineering (MCQ) questions and answers for Q. 10179

Q.  In monotropic system, transition of one polymorph to another is _____
- Published on 11 Sep 15

a. reversible
b. irreversible
c. either a or b
d. none of the above

ANSWER: irreversible

Related Content

 

    Discussion

  • Sravanthi   -Posted on 20 Nov 15
    - The ability of a solid material to exist in more than one crystal structure under creep variation is called as polymorphism.

    - Polymorphism is further classified into two types:

    1) Monotropic system: Transition from one polymorph to another is irreversible which means that a plot of free energy of different polymorphs against temperature do not cross unless all polymorphs melt. e.g. Al2O3

    2) Enantiotropic system: In this system, a plot of free energy against temperature depicts a crossing point before different polymorphs melt. This means that they can be converted reversibly by heating and cooling. e.g. Fe, Zr, etc.

➨ Post your comment / Share knowledge


Enter the code shown above:

(Note: If you cannot read the numbers in the above image, reload the page to generate a new one.)
▲