Question

According to Gibbs phase rule for a 2-component system under condensed rule, what observation can be made within the equilibrium phase?

(a) T can be varied independently

(b) Varying a T value fixes the equilibrium compositions

(c) Neither T nor concentration can be varied respectively

(d) 2 phases cannot coexist

This question was addressed to me in examination.

My doubt is from Application of Phase Rule to One Component System topic in division Phase Rule of Engineering Chemistry I

Answer 1

The correct option is (b) Varying a T value fixes the equilibrium compositions

The explanation is: During invariant position of the system (equilibrium state), sometimes due to increase in colligative properties of materials, the equilibrium faces a shift slightly. In this case, the equilibrium can be brought back by varying T values.