The mass of a non-volatile, non-electrolyte solute (molar mass=50 g ) needed to be dissolved in 114 g octane to reduce its vapour pressure to 75%, is :
For 1 molal aqueous solution of the following compounds, which one will show the highest freezing point ?
Two 5 molal solutions are prepared by dissolving a non-electrolyte non-volatile solute separately in the solvents X and Y. The molecular weights of the solvents are MX and MY , respectively where
. The relative lowering of vapour pressure of the solution in X is “m” times that of the solution in Y. Given that the number of moles of solute is very small in comparison to that of solvent, the value of “m” is :