JEE Main & Advanced Chemistry Solutions / विलयन Sample Paper Topic Test - Solutions

  • question_answer
    Two components A and B form an ideal solution. The mole fraction of A and B in ideal solutions are \[{{X}_{A}}\] and  \[{{X}_{B}},\] while that of in vapour phase, these components have their mole fractions as \[{{Y}_{A}}\] and \[{{Y}_{B}}\] then, the slope and intercept of plot of \[\frac{1}{{{Y}_{A}}}\] us \[\frac{1}{{{X}_{A}}}\] will be

    A) \[\frac{p_{B}^{0}}{p_{A}^{0}},\frac{p_{A}^{0}-p_{B}^{0}}{p_{A}^{0}}\]

    B) \[\frac{p_{B}^{0}}{p_{A}^{0}},\frac{p_{A}^{0}+p_{B}^{0}}{p_{A}^{0}}\]

    C) \[\frac{p_{A}^{0}}{p_{B}^{0}},\frac{p_{A}^{0}+p_{B}^{0}}{p_{A}^{0}}\]

    D) \[\frac{p_{A}^{0}}{p_{B}^{0}},\frac{p_{A}^{0}}{p_{A}^{0}-p_{B}^{0}}\]

    Correct Answer: A

    Solution :

    [a] Idea This problem includes the concept of Raoult's law and their representation as equation of straight line. While solving this problem, student is advised to follow given tips.
    • Write the partial pressure equation using Raoult's law.
    • Put the value of partial pressure to calculate mole fractions.
    • Rearrange the equation in \[\frac{1}{{{Y}_{A}}}\] us \[\frac{1}{{{X}_{A}}}\] and determine slope and intercept.
                \[{{p}_{A}}={{X}_{A}}p_{A}^{0}\]
                \[{{p}_{B}}={{X}_{B}}p_{B}^{0}\]
    and      \[{{Y}_{A}}=\frac{{{p}_{A}}}{{{p}_{A}}+{{p}_{B}}}=\frac{p_{A}^{0}{{X}_{A}}}{p_{A}^{0}{{X}_{A}}+p_{B}^{0}(1-{{X}_{A}})}\]
                \[{{Y}_{A}}=\frac{p_{A}^{0}{{X}_{A}}}{{{X}_{A}}(p_{A}^{0}-p_{B}^{0})+p_{B}^{0}}\]
                \[\frac{1}{{{Y}_{A}}}=\left( \frac{p_{A}^{0}-p_{B}^{0}}{p_{A}^{0}} \right)+\frac{p_{B}^{0}}{p_{A}^{0}}\frac{1}{{{X}_{A}}}\]
    So, slope \[\frac{p_{B}^{0}}{p_{A}^{0}}\] and intercept \[\frac{p_{A}^{0}-p_{B}^{0}}{p_{A}^{0}}\]
    TEST Edge Students are advised to study Raoult's law for non-ideal solution which may be asked frequently.


You need to login to perform this action.
You will be redirected in 3 sec spinner