Question

IN refractories, transitions such as α⇄β quartz or quartz ⇄ cristobalite have which of the following effect?

(a) Nasser’s effect

(b) Crystal effect

(c) Dislocation effect

(d) Deleterious effect

I had been asked this question by my college director while I was bunking the class.

I want to ask this question from Applications of DTA and TGA topic in division Thermal Analysis of Solid State Chemistry

Answer 1

Correct option is (d) Deleterious effect

Explanation: During the, transitions such as α⇄β quartz or quartz ⇄ cristobalite, deleterious effect is observed on silica refractories because volume changes associated with each transition reduce the mechanical strength of the refractory. These transitions, which should be prevented from occurring if possible, may be monitored by DTA (differential thermal analysis).