Chapter 12, Problem 60E

Interpretation Introduction

Interpretation:

The reason for a triple point of water to be better fixed point for establishing a thermometric scale rather than melting point and boiling point.

Concept introduction:

A fixed point in thermometry is a convention that is used as a reference to measure other values. The phase diagram is used to study the phase changes of different chemicals under different pressure and temperature conditions. In the phase diagram of water, at triple point, water coexists in three phases, gas, liquid and solid in a thermodynamic equilibrium at a specified temperature and pressure.