Colligative Properties Questions

Equimolar solutions in the same solvent have:

A $5.25\%$ solution of a substance is isotonic with a $1.5\%$ solution of urea (molar mass $=60{\text{g mol}}^{-1}$) in the same solvent. If the densities of both the solutions are assumed to be equal to $1.0{\text{g cm}}^{-3}$, molar mass of the substance will be:

Which one of the following aqueous solutions will exhibit the highest boiling point?

Which one of the following statements is false?

The vapour pressure of water at $20^{\circ }\text{C}$ is $17.5\text{mm Hg}$. If $18\text{g}$ of glucose (${\text{C}}_6{\text{H}}_{12}{\text{O}}_6$) is added to $178.2\text{g}$ of water at $20^{\circ }\text{C}$, the vapour pressure of the resulting solution will be:

If sodium sulphate is considered to be completely dissociated into cations and anions in aqueous solution, the change in freezing point of water ($\Delta T_f$), when $0.01\text{mol}$ of sodium sulphate is dissolved in $1\text{kg}$ of water, is ($K_f=1.86{\text{K kg mol}}^{-1}$):

$K_f$ for water is $1.86{\text{K kg mol}}^{-1}$. If your automobile radiator holds $1.0\text{kg}$ of water, how many grams of ethylene glycol (${\text{C}}_2{\text{H}}_6{\text{O}}_2$) must you add to get the freezing point of the solution lowered to $-2.8^{\circ }\text{C}$?