How many grams of a non-volatile solute with a molar mass of $90$ must be dissolved in $97.5 \ g$ of water to cause a $2.5 \%$ decrease in vapour pressure?

$3 \ g$ of urea is dissolved in $45 \ g$ of $H_2O$. The relative lowering in vapour pressure is

What is the vapor pressure of a solution containing a solid solute and a liquid solvent?

The vapour pressure of a solution of methyl alcohol and ethyl alcohol is represented as $P = 115 X_A + 140$,where $X_A$ is the mole fraction of methyl alcohol. The value of $\lim_{X_A \to 0} \frac{P_B^o}{X_B}$ is

$A$ solution containing $30 \, g$ of non-volatile solute in exactly $90 \, g$ water has a vapour pressure of $21.85 \, mm \, Hg$ at $25 \, ^oC$. Further $18 \, g$ of water is then added to the solution. The resulting solution has a vapour pressure of $22.15 \, mm \, Hg$ at $25 \, ^oC$. Calculate the molecular weight of the solute.

When $25 \ g$ of a non-volatile solute is dissolved in $100 \ g$ of water,the vapour pressure is lowered by $2.25 \times 10^{-1} \ mm$. If the vapour pressure of water at $20^{\circ}C$ is $17.5 \ mm$,what is the molecular weight of the solute?