Answer the following:

The triple-point of water is a standard fixed point in modern thermometry. Why? What is wrong in taking the melting point of ice and the boiling point of water as standard fixed points (as was originally done in the Celsius scale)?

Asked by Topperlearning User | 15th Apr, 2015, 10:39: AM

Expert Answer:

It is because of the fact that triple point of a substance is unique, i.e. it occurs at one particular set of values of pressure and temperature. The melting point of ice and boiling point of water are not unique. They change with change in value of pressure or due to the presence of impurities in water.

Answered by  | 15th Apr, 2015, 12:39: PM