The temperature at which the molar specific volumes for liquid and vapor phases become equal is termed as:

Question

Question

This question was previously asked in

AAI ATC Junior Executive 2015 Official Paper (Shift 2)

Answer 1

Concept:

It is the point at which the slope changes from positive to negative and at this point the slope is zero.

F1 S.C Madhu 08.05.20 D12

It represents the highest pressure and temperature at which the liquid and vapor phases coexist in equilibrium.
All the thermodynamic properties of liquid and vapor phases are identical at the critical point.
The critical point is the point at which the liquid and vapor phases are not distinguishable, hence molar specific volumes for liquid and vapor phases will be equal.
The temperature pressure and volume at the critical point are called critical temperature Tc , critical pressure Pc, and critical volume Vc
It is a fixed point that’s why the degree of freedom will be zero.
Dryness fraction (x) is not defined at the critical point.

Note:

The critical point properties of water are

Pc = 221.2 bar

Tc = 374.15° C

Vc = 0.00317 m3/kg