Answers

Sanjay Rawat
Feb 9, 2019

Triple point of a substance is the temperature and pressure at which the three phases (gas, liquid, and solid) of that substance coexist in thermodynamic equilibrium .


A critical point (or critical state) is the end point of a phase equilibrium .  Triple point of a substance is the temperature and pressure at which the three phases (gas, liquid, and solid) of that substance coexist in thermodynamic equilibrium . It is represented by a point on p-v-T surface It is represented by a point on p-T diagram but appears as a line on p-v-T surface .  A basic introduction to the triple point of water, which is the state where water can exist simultaneously in a liquid, solid, and gaseous form.

At critical point there is no distinction between the liquid and vapour phases . below critical point the substances exists in a two phases At triple point all the three phases can coexist together in equilibrium .The triple point describes the point where three phases (usually solid, liquid, and gas) of a material exist in equilibrium with one another.

Critical Point : The most prominent example is the liquid-vapor critical point, the end point of the pressure-temperature curve that designates conditions under which a liquid and its vapor can coexist.

Triple Point : For example :  For example, the triple point of mercury occurs at a temperature of -38.83440 °C and a pressure of 0.2 mPa.

The triple point of water is defined to take place at 273.16 K, where K is the SI unit Kelvin. Unlike Celsius and Fahrenheit scales, Kelvin is not measured using degrees; we merely say "Kelvin."

The triple point of water is important enough to merit its own line:

T3 = 273.1K

This is equivalent to 0.01oC and 32.02oF, and thus we use T3 to help set the freezing point of water.