Question

Which of the following is the condition for the boiling of a liquid?

(a) Absolute pressure of a liquid must be greater than or equal to it’s vapor pressure

(b) Absolute pressure of a liquid must be less than or equal to it’s vapor pressure

(c) Absolute pressure of a liquid must be equal to it’s vapor pressure

(d) Absolute pressure of a liquid must be greater than it’s vapor pressure

I had been asked this question during an internship interview.

I'd like to ask this question from Vapor Pressure in division Properties of Fluids of Fluid Mechanics

Answer 1

Correct option is (b) Absolute pressure of a liquid must be less than or equal to it’s vapor pressure

Easiest explanation: As the absolute pressure of a liquid goes below it’s vapor pressure, the formation of vapor bubbles start. Thus, for boiling to start, the absolute pressure of a liquid must be less than or equal to it’s vapor pressure.