Question

A constant pressure air thermometer gave a reading of $47.5$ units of volume when immersed in ice-cold water, and $67$ units in a boiling liquid. The boiling point of the liquid, is

• A. 125${}^{\circ }$C
• B. 100${}^{\circ }$C
• C. 135${}^{\circ }$C
• D. 112${}^{\circ }$C

Answer 1

Answer: (D)

Given: Initial volume $\left(V_1\right)=47\times 5$ units;
Temperature of icecold water $\left(T_1\right)=0^{\circ }C=273K$
and final volume $\left(V_2\right)=67$ units.
We know from the Charles law,
$\frac{V_1}{T_1}=\frac{V_2}{T_2}$ or
$T_2=\frac{V_3}{V_1}\times T_1$
$=\frac{67}{47\times 5}\times 273=385K=112^{\circ }C$
$T_2$ is the boiling point of the liquid.