GATE 2026 Chemical Engineering, Q16 · Thermodynamics
The correct answer is B, 0.
Question
According to the phase rule, which one of the following is the number of degrees of freedom for pure water at its triple point?
Official answer: 0
Why
GATE 2026 official key: (B). F = C − P + 2 = 1 − 3 + 2 = 0 at the triple point (solid + liquid + vapor of one component).
Explanation cross-checked for consistency. Final answer matches the official IIT answer key.