If chi1 and chi2 represent the mole fractions of a component A in the vapour phase and liquid mixture respectively, and p°A and p°B represent vapour pressures of pure A and pure B, then total vapour pressure of liquid mixture is

Question

If chi1 and chi2 represent the mole fractions of a component A in the vapour phase and liquid mixture respectively, and p°A and p°B represent vapour pressures of pure A and pure B, then total vapour pressure of liquid mixture is (A)  (ρ°A chi1/ chi2)  (B)  (ρ°A chi2/ chi1)  (C)  (ρ°B chi1/ chi2)  (D)  (ρ°B chi2/ chi1)

Tardigrade Admin · Accepted Answer

Mole fraction in the vapour phase ( chi1)=(pA/ptotal) But, PA× chiA× pA°= chi2pA° or chi1× pA° = chi2 p°A (as chiA= chi1) ∴ chi1=( chi2pA°/ptotal) or ptotal=(p°A chi2/ chi1)

Q. If $χ_{1}$ and $χ_{2}$ represent the mole fractions of a component $A$ in the vapour phase and liquid mixture respectively, and $p_{A}^{\circ}$ and $p_{B}^{\circ}$
represent vapour pressures of pure $A$ and pure $B$ , then total vapour pressure of liquid mixture is

$\frac{ρ _{A}^{\circ} χ _{1}}{χ _{2}}$

$\frac{ρ _{A}^{\circ} χ _{2}}{χ _{1}}$

$\frac{ρ _{B}^{\circ} χ _{1}}{χ _{2}}$

$\frac{ρ _{B}^{\circ} χ _{2}}{χ _{1}}$

Q. If χ1​ and χ2​ represent the mole fractions of a component A in the vapour phase and liquid mixture respectively, and pA∘​ and pB∘​ represent vapour pressures of pure A and pure B, then total vapour pressure of liquid mixture is

χ2​ρA∘​χ1​​

χ1​ρA∘​χ2​​

χ2​ρB∘​χ1​​

χ1​ρB∘​χ2​​

Mole fraction in the vapour phase (χ1​)=ptotal​pA​​ But, PA​×χA​×pA∘​=χ2​pA∘​ or χ1​×pA∘​=χ2​pA∘​(asχA​=χ1​) ∴χ1​=ptotal​χ2​pA∘​​ or ptotal​=χ1​pA∘​χ2​​

Q. If $χ_{1}$ and $χ_{2}$ represent the mole fractions of a component $A$ in the vapour phase and liquid mixture respectively, and $p_{A}^{\circ}$ and $p_{B}^{\circ}$
represent vapour pressures of pure $A$ and pure $B$ , then total vapour pressure of liquid mixture is

$\frac{ρ _{A}^{\circ} χ _{1}}{χ _{2}}$

$\frac{ρ _{A}^{\circ} χ _{2}}{χ _{1}}$

$\frac{ρ _{B}^{\circ} χ _{1}}{χ _{2}}$

$\frac{ρ _{B}^{\circ} χ _{2}}{χ _{1}}$