Which of the following aqueous solutions containing $10 \ g$ of solute in each case has the highest boiling point $(B.P.)$?

$x \ g$ of urea (molar mass $60 \ g \ mol^{-1}$) is completely dissolved in $y \ g$ of pure water and the solution boiled at $373.202 \ K$. If the boiling point of pure water at $1.013 \ bar$ is $373.15 \ K$, then $x:y$ is $(K_b(H_2O) = 0.52 \ K \ kg \ mol^{-1})$

$0.15 \ g$ of a solute is dissolved in $15 \ g$ of a solvent. If the solution boils at a temperature $0.215 \ K$ higher than the boiling point of the pure solvent,what is the molar mass of the solute? $(K_b = 2.15 \ K \ kg \ mol^{-1})$

Give the unit for the molal elevation constant in boiling point.

Boiling point of water at $750 \, mm \, Hg$ is $99.63^{\circ} \, C$. How much sucrose is to be added to $500 \, g$ of water such that it boils at $100^{\circ} \, C$?

When salt is dissolved in water,then.....