Andhra Pradesh Board Solutions for Chapter: Solutions, Exercise 4: Intext Questions

Vapour pressure of pure water at $298 \mathrm{K}$ is $23.8 \mathrm{mm} \mathrm{Hg}. 50 \mathrm{g}$ of urea $\left({\mathrm{NH}}_2{\mathrm{CONH}}_2\right)$ is dissolved in $850 \mathrm{g}$ of water. Calculate the vapour pressure of water for this solution and its relative lowering.

Boiling point of water at $750 \mathrm{mm} \mathrm{Hg}$is $99.{63}^{°}\mathrm{C}$. How much sucrose is to be added to $500 \mathrm{g}$ of water such that it boils at ${100}^{°}\mathrm{C}$. ${\mathrm{K}}_{\mathrm{b}}$ for water is $0.52 \mathrm{K} \mathrm{kg} {\mathrm{mol}}^{-1}$.

Calculate the mass of ascorbic acid $\left(\mathrm{Vitamin} \mathrm{C}, {\mathrm{C}}_6{\mathrm{H}}_8{\mathrm{O}}_6\right)$ to be dissolved in $75 \mathrm{g}$ of acetic acid to lower its melting point by $1.5^0\mathrm{C}. {\mathrm{K}}_{\mathrm{f}}=3.9 \mathrm{K} \mathrm{kg} {\mathrm{mol}}^{-1}$. 

Calculate the osmotic pressure in pascals exerted by a solution prepared by dissolving $1.0 \mathrm{g}$ of polymer of molar mass $185,000$ in $450 \text{mL}$ of water at ${37}^0\mathrm{C}$.