Liquid A and B form ideal solution for all compositions of A and B at 25° C. Two such solutions with 0.25 and 0.50 mole fractions of A have the total vapour pressures of 0.3 and 0.4 bar, respectively. What is the vapour pressure of pure liquid B in bar?

Question

Liquid A and B form ideal solution for all compositions of A and B at 25° C. Two such solutions with 0.25 and 0.50 mole fractions of A have the total vapour pressures of 0.3 and 0.4 bar, respectively. What is the vapour pressure of pure liquid B in bar? (A)  (B)  (C)  (D)

Tardigrade Admin · Accepted Answer

0.3=pA0 × 0.25+pB0 × 0.75 .... (1) 0.4=pA0 × 0.50+pB0 × 0.50 .... (2) On solving, p B 0=0.20 bar and p A 0=0.6 bar

Q. Liquid $A$ and $B$ form ideal solution for all compositions of $A$ and $B$ at $2 5^{\circ} C$ . Two such solutions with $0.25$ and $0.50$ mole fractions of $A$ have the total vapour pressures of $0.3$ and $0.4$ bar, respectively. What is the vapour pressure of pure liquid $B$ in bar?

$0.3 = p_{A}^{0} \times 0.25 + p_{B}^{0} \times 0.75$ .... (1)
$0.4 = p_{A}^{0} \times 0.50 + p_{B}^{0} \times 0.50$ .... (2)
On solving, $p_{B}^{0} = 0.20$ bar and $p_{A}^{0} = 0.6$ bar

Q. Liquid A and B form ideal solution for all compositions of A and B at 25∘C. Two such solutions with 0.25 and 0.50 mole fractions of A have the total vapour pressures of 0.3 and 0.4 bar, respectively. What is the vapour pressure of pure liquid B in bar?

0.3=pA0​×0.25+pB0​×0.75 .... (1) 0.4=pA0​×0.50+pB0​×0.50 .... (2) On solving, pB0​=0.20 bar and pA0​=0.6 bar

Q. Liquid $A$ and $B$ form ideal solution for all compositions of $A$ and $B$ at $2 5^{\circ} C$ . Two such solutions with $0.25$ and $0.50$ mole fractions of $A$ have the total vapour pressures of $0.3$ and $0.4$ bar, respectively. What is the vapour pressure of pure liquid $B$ in bar?

$0.3 = p_{A}^{0} \times 0.25 + p_{B}^{0} \times 0.75$ .... (1)
$0.4 = p_{A}^{0} \times 0.50 + p_{B}^{0} \times 0.50$ .... (2)
On solving, $p_{B}^{0} = 0.20$ bar and $p_{A}^{0} = 0.6$ bar