Respuesta :

Raoult's Law basically states that the vapor pressure of a solution equals the sum of the vapor pressures of each volatile component, if it was multiplied by that mole fraction of the component in solution.

Explanation:

Raoult's law for volatile solutes states that at a given temperature vapor pressure of a component is equal to the mole fraction of that component component in the solution multiplied to the vapor pressure of the component in the pure state.

Mathematically,     [tex]p_{A} = p^{o}_{A} \times x_{A}[/tex]

                              [tex]p_{B} = p^{o}_{B} \times x_{B}[/tex]

                              P = [tex]p_{A} + p_{B}[/tex]

                                 = [tex]p^{o}_{A} \times x_{A} + p^{o}_{B} \times x_{B}[/tex]

Since,  [tex]x_{A} + x_{B}[/tex] = 1

           [tex]x_{A}[/tex] = 1 - [tex]x_{B}[/tex]

hence,    P = [tex]p^{o}_{A} \times (1 - x_{B}) + p^{o}_{B} \times x_{B}[/tex]

              P = [tex](p^{o}_{B} - p^{o}_{A})x_{B} + p^{o}_{A}[/tex]

On the other hand, Raoult's law for non-volatile solutes states that relative lowering of vapor pressure of a solution that has non-volatile solute is equal to the mole fraction of the solute in the solution.

Mathematically,       [tex]\frac{p^{o} - P_{s}}{P^{o}}[/tex] = [tex]\frac{n_{2}}{n_{1} + n_{2}}[/tex] = [tex]x_{2}[/tex]

where,    [tex]x_{2}[/tex] = mole fraction of solute

               [tex]n_{1}[/tex] = moles of solvent

               [tex]n_{2}[/tex] = moles of solute

               [tex]P_{s}[/tex] = vapor pressure of the solution

               [tex]p^{o}[/tex] = vapor pressure of pure solvent