Chemistry - Liquid Solution Question with Solution | TestHub

Relative lowering of vapour pressure

Equation$\frac{{\mathrm{P}}^0-{\mathrm{P}}_{\mathrm{s}}}{{\mathrm{P}}^0}={\mathrm{X}}_{\mathrm{s}\mathrm{o}\mathrm{l}\mathrm{u}\mathrm{t}\mathrm{e}}=\frac{\mathrm{n}}{\mathrm{n}+\mathrm{N}}$

Modified forms of equation is$\frac{{\mathrm{P}}^0-{\mathrm{P}}_{\mathrm{s}}}{{\mathrm{P}}_{\mathrm{s}}}=\frac{\mathrm{n}}{\mathrm{N}}$

n = moles of solute, N = moles of solvent

${\mathrm{P}}^0=760$torr

${\mathrm{P}}_{\mathrm{s}}=?$

$\frac{760-{\mathrm{P}}_{\mathrm{s}}}{{\mathrm{P}}_{\mathrm{s}}}=\frac{\frac{18}{180}}{\frac{178.2}{18}}$

${\mathrm{P}}_{\mathrm{s}}=752.4$torr