Question

What does Raoult's law state?

a. The vapor pressure of a pure solvent is higher than that of a solution containing that solvent.

b. The vapor pressure of a pure solvent is lower than that of a solution containing that solvent.

c. The vapor pressure of a solute is the same as the vapor pressure of the solvent.

d. The vapor pressure of a solute is greater than that of a pure solvent.

Answer 1

Correct Answer is A:  The vapor pressure of a pure solvent is higher than that of a solution containing that solvent.

Reason
According to Raoult's Law states that vapor pressure of each component in the solution is equal to the vapor pressure of the pure component multiplied by its mole fraction. It is mathematically expressed as
P = X $P^{0}$
where, P = vapor pressure of solution
X = mole fraction of solute
P^{0} [/tex] = vapor pressure of pure component

Here X is always less than one (in solutions)

∴ P < P^{0} [/tex]

Answer 2

Raoult's law states That the vapor pressure of a pure solvent is higher than that of a solution containing that solvent. This is a law of thermodynamics established by French chemist François-Marie Raoultin in 1887. This shows that  partial vapor pressure  is equal to the vapour pressure.