Question

Which of the following is the formula for condense phase rule?

(a) F=C-P+2

(b) F=C-P+1

(c) F=C+P-2

(d) F=C+P-1

The question was asked in an online quiz.

I want to ask this question from Gibb’s Phase Rule in division Phase Rule of Engineering Chemistry I

Answer 1

The correct answer is (b) F=C-P+1

For explanation: In a condensed phase rule system, the phases are represented in three dimension which is not suitable for graphic purposes and hence the pressure is considered to be zero (this is helpful in drawing 2D images). Hence the formula reduces to F=C-P+2.