Answer:
Vapor pressure of the solution is 22.9 torr at 25°C
Explanation:
When a non volatile solute is added to a pure solvent, the vapour pressure of the mixture decrease regard to the pure solvent following the equation (Raoult's law):
[tex]P_{solution}=X_{solvent}.P^0_{solvent}[/tex]
Where vapour pressure of the pure solvent (Water) is 23.8torr at 25°C.
Mole fraction of water is the ratio between moles of water and total moles in solution. The solution has a mole fraction of water of:
[tex]X_{water}=\frac{8.0Moles_{water}}{0.30mol_{Na_2SO_4}+8.0mol_{water}} = 0.9639[/tex]
Replacing in Raoult's law:
[tex]P_{solution}=0.9639*23.8torr[/tex]
