Embibe Experts Solutions for Chapter: Solutions, Exercise 1: ICSE-2019

An aqueous solution containing $12.48 \mathrm{g}$ of barium chloride in $1000 \mathrm{g}$ of water boils at $100.0832℃$. Calculate the degree of dissociation of barium chloride. 
(${\mathrm{K}}_{\mathrm{b}}$ for water $= 0.52 \mathrm{K} \mathrm{Kg} {\mathrm{mol}}^{-1}$)

Calculate the boiling point of urea solution when $6 \mathrm{g}$ of urea is dissolved in $200 \mathrm{g}$ of water. (${\mathrm{K}}_{\mathrm{b}}$ for water $= 0.52 \mathrm{K} \mathrm{kg} {\mathrm{mol}}^{-1}$, boiling point of pure water $= 373 \mathrm{K}$, molecular weight of urea $= 60$).

The elevation in boiling point when $0.30 \mathrm{g}$ of acetic acid is dissolved in $100 \mathrm{g}$ of benzene is $0.0633 °\mathrm{C}$. Calculate the molecular weight of acetic acid from this data. What conclusion can you draw about the molecular state of the solute in the solution? (Given ${\mathrm{K}}_{\mathrm{b}}$ for benzene $=2.53 \mathrm{K} \mathrm{kg} {\mathrm{mol}}^{-1}$, at. wt. of $\mathrm{C}=12, \mathrm{H}=1, \mathrm{O}=16$).

Determine the osmotic pressure of a solution prepared by dissolving $0.025 \mathrm{g}$ of ${\mathrm{K}}_2{\mathrm{SO}}_4$ in $2$ litres of water at $25 °\mathrm{C}$, assuming that ${\mathrm{K}}_2{\mathrm{SO}}_4$ is completely dissociated. 

($\mathrm{R}=0.0821 \mathrm{L} \mathrm{atm} {\mathrm{K}}^{-1}{\mathrm{mol}}^{-1}; \mathrm{Mol}. \mathrm{wt}. \mathrm{of} {\mathrm{K}}_2{\mathrm{SO}}_4=174 \mathrm{g} {\mathrm{mol}}^{-1}$).

An aqueous solution of a non-volatile solute freezes at $272.4 \mathrm{K}$, while pure water freezes at $273.0 \mathrm{K}$. Determine the following: The molality of solution. (Given:${\mathrm{K}}_{\mathrm{f}}=1.86 \mathrm{K} \mathrm{kg} {\mathrm{mol}}^{-1}, {\mathrm{K}}_{\mathrm{b}}=0.512 \mathrm{K} \mathrm{kg} {\mathrm{mol}}^{-1}$ and vapour pressure of water at $298 \mathrm{K}=23.756 \mathrm{mm} \mathrm{of} \mathrm{Hg}$).

An aqueous solution of a non-volatile solute freezes at $272.4 \mathrm{K}$, while pure water freezes at $273.0 \mathrm{K}$. Determine the following: Boiling point of solution. (Given: ${\mathrm{K}}_{\mathrm{f}}=1.86 \mathrm{K} \mathrm{kg} {\mathrm{mol}}^{-1}, {\mathrm{K}}_{\mathrm{b}}=0.512 \mathrm{K} \mathrm{kg} {\mathrm{mol}}^{-1}$ and vapour pressure of water at $298 \mathrm{K}=23.756 \mathrm{mm} \mathrm{of} \mathrm{Hg}$).

An aqueous solution of a non-volatile solute freezes at $272.4 \mathrm{K}$, while pure water freezes at $273.0 \mathrm{K}$. Determine the following: The lowering of vapour pressure of water at $298 \mathrm{K}$. (Given: ${\mathrm{K}}_{\mathrm{f}}=1.86 \mathrm{K} \mathrm{kg} {\mathrm{mol}}^{-1}, {\mathrm{K}}_{\mathrm{b}}=0.512 \mathrm{K} \mathrm{kg} {\mathrm{mol}}^{-1}$ and vapour pressure of water at $298 \mathrm{K}=23.756 \mathrm{mm} \mathrm{of} \mathrm{Hg}$).

A solution containing $1.23 \mathrm{g}$ of calcium nitrate in $10 \mathrm{g}$ of water, boils at $100.975 °\mathrm{C}$ at $760 \mathrm{mm} \mathrm{of} \mathrm{Hg}$. Calculate the Van’t Hoff factor for the salt at this concentration. (${\mathrm{K}}_{\mathrm{b}}$ for water $=0.52 \mathrm{K} \mathrm{kg} {\mathrm{mol}}^{-1}$, mol. wt. of calcium nitrate $=164 \mathrm{g} {\mathrm{mol}}^{-1}$).