Question

The liquid phase of a pure substance is termed as \(\underline{\hspace{2cm}}\), if its temperature is lower than the saturation temperature corresponding to its pressure \(P\).

• A. super-heated liquid
• B. sub-cooled liquid
• C. metastable liquid
• D. flashing liquid

Hint:

A sub-cooled liquid has a temperature below its saturation point at a given pressure.

Answer 1

The Correct Option is B

When the temperature of a liquid is lower than its saturation temperature corresponding to its pressure, the liquid is referred to as a sub-cooled liquid. This condition occurs when the liquid is not boiling, and its temperature is lower than the boiling point at the given pressure.

Step 1: Understand the phases of liquid.
- Super-heated liquid: This is a liquid that has been heated above its saturation temperature at a given pressure.
- Sub-cooled liquid: This is the correct term when the liquid's temperature is lower than its saturation temperature.
- Metastable liquid: This refers to a liquid that is in a non-equilibrium state, often unstable, but not the correct term for sub-cooled liquid.
- Flashing liquid: This refers to a liquid that undergoes a phase change to vapor under reduced pressure.

Step 2: Conclusion.
The liquid phase is termed sub-cooled liquid when its temperature is lower than the saturation temperature at the given pressure.

Final Answer: \text{(B) sub-cooled liquid}