2. Solved Papers
  3. NEET
  4. Chemistry

NEET Chemistry NEET PYQ-Solutions

  • question_answer
    \[{{p}_{A}}\] and \[{{p}_{B}}\] are the vapour pressure of pure liquid components, A and B, respectively of an ideal binary solution. If \[{{x}_{A}}\] represents the mole fraction of component A, the total pressure of the solution will be [AIPMT (S) 2012]

    A) \[{{p}_{A}}+{{x}_{A}}({{p}_{B}}-{{p}_{A}})\]

    B) \[{{p}_{A}}+{{x}_{A}}({{p}_{A}}-{{p}_{B}})\]

    C) \[{{p}_{B}}+{{x}_{A}}({{p}_{B}}-{{p}_{A}})\]

    D) \[{{p}_{B}}+{{x}_{A}}({{p}_{A}}-{{p}_{B}})\]

    Correct Answer: D

    Solution :

    [d] Total pressure,\[{{p}_{T}}=p{{'}_{A}}+p{{'}_{B}}\]                        ...(i)
    We know that, \[p{{'}_{A}}={{p}_{A}}{{x}_{A}}\]
                            \[p{{'}_{B}}={{p}_{B}}{{x}_{B}}\]
    Substituting the values of \[p{{'}_{A}}\]and \[p{{'}_{B}}\] in Eq. (i)
                \[{{p}_{T}}={{p}_{A}}{{x}_{A}}+{{p}_{B}}{{x}_{B}}\]
    \[[{{x}_{A}}+{{x}_{B}}=1\Rightarrow {{x}_{A}}=1-{{x}_{B}}or\,{{x}_{B}}=1-{{x}_{A}}]\]
                \[={{p}_{A}}{{x}_{A}}+{{p}_{B}}(1-{{x}_{A}})\]
                \[={{p}_{A}}{{x}_{A}}+{{p}_{B}}-{{p}_{B}}{{x}_{A}}\]
    \[\therefore \]      \[{{p}_{T}}x{{p}_{B}}+{{x}_{A}}({{p}_{A}}-{{p}_{B}})\]


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