Question:
Use $\mathrm{R}=8.3 \mathrm{~J} / \mathrm{mol}-\mathrm{K}$ wherever required.
A glass contains some water at room temperature $20^{\circ} \mathrm{C}$. Refrigerated water is added to it slowly. When the temperature of the glass reaches $10^{\circ} \mathrm{C}$, small droplets condense on the outer surface. Calculate the humidity in the room. The boiling point of water at a pressure of $17.5 \mathrm{~mm}$ of mercury is $20^{\circ} \mathrm{C}$ and at $8.9$ $\mathrm{mm}$ of mercury it is $10^{\circ} \mathrm{C}$.
Solution: