Question

A constant-volume thermometer registers a pressure of 1.500 × 10⁴ Pa at the triple point of water and a pressure of 2.050 × 10⁴ Pa at the normal boiling point. What is the temperature at the normal boiling point?

Answer 1

Given:
Pressure registered by a constant-volume thermometer at the triple point, P_tr = 1.500 × 10⁴ Pa
Pressure registered by the thermometer at the normal boiling point, P = 2.050 × 10⁴ Pa
We know that for a constant-volume gas thermometer, temperature (T) at the normal boiling point is given as:
$$\begin{gathered} T=\frac{P}{P_{tr}}\times 273.16\mathrm{K} \\ \Rightarrow T=\frac{2.050\times {10}^4}{1.500\times {10}^4}\times 273.16\mathrm{K} \\ \Rightarrow T=373.31\mathrm{K} \end{gathered}$$
Therefore, the temperature at the normal point (T) is 373.31 K.