Question

The pressure of the gas in a constant volume gas thermometer is 70 kPa at the ice point. Find the pressure at the steam point.

Answer 1

$P_1$ = 70 KPa, $P_2$ = ?

$T_1$ = 273 K $T_2$ = 373 K

$T_1=\frac{P_1}{P_{tr}}\times 273.16$

$\Rightarrow 273=\frac{70}{P_{tr}}\times {10}^3\times 273.16$

$\Rightarrow P_{tr}=\frac{70\times 273.16\times {10}^3}{273}$

Again, $T_2=\frac{P_2\times 273.16}{P_{tr}}$

$\Rightarrow 373=\frac{P_2\times 273\times 273.16}{70\times 273.16\times {10}^3}$

$\Rightarrow P_2=\frac{373\times 70\times {10}^3}{273}=95.6\text{KPa}$