The number of degrees of freedom for an azeotropic mixture in a two component vapour-liquid equilibria is/are

A. Zero

B. One

C. Two

D. Three

Answer: Option B

Solution(By Examveda Team)

Degree of freedom = $$C - \emptyset + 2$$
For azeotropic binary mixture since number of components$$(c) = 2$$
Number of phases$$(∅) = 2$$
Degree of freedom $$= 2$$
But for azeotropic mixture since vapor composition $$=$$ liquid composition
Degree of freedom becomes $$= 1$$