JEE Main & Advanced JEE Main Paper (Held On 19 April 2014)

  • question_answer
    For the decomposition of the compound, represented as\[N{{H}_{2}}COON{{H}_{4}}(s)2N{{H}_{3}}(g)+C{{O}_{2}}(g)\] the \[{{K}_{p}}=2.9\times {{10}^{-5}}at{{m}^{3}}.\] If the reaction is started with 1 mol of the compound, the total pressure at equilibrium would be :     JEE Main Online Paper (Held On 19 April 2016)

    A) \[1.94\times {{10}^{-2}}atm\]    

    B) \[5.82\times {{10}^{-2}}atm\]

    C) \[7.66\times {{10}^{-2}}atm\]    

    D) \[38.8\times {{10}^{-2}}atm\]

    Correct Answer: B

    Solution :

    \[N{{H}_{2}}COON{{H}_{4}}(s)2N{{H}_{3}}(g)+C{{O}_{2}}(g)\] \[{{K}_{P}}=\frac{{{\left( {{P}_{N{{H}_{3}}}} \right)}^{2}}\times \left( {{P}_{C{{O}_{2}}}} \right)}{{{P}_{N{{H}_{2}}COON{{H}_{4}}}}(s)}={{\left( {{P}_{N{{H}_{3}}}} \right)}^{2}}\times \left( {{P}_{C{{O}_{2}}}} \right)\] As evident by the reaction, \[N{{H}_{3}}\] and \[C{{O}_{2}}\] are formed in molar ratio of 2 : 1. Thus if P is the total pressure of the system at equilibrium, then \[{{P}_{N{{H}_{3}}}}=\frac{2\times P}{3}\]                        \[{{P}_{C{{O}_{2}}}}=\frac{1\times P}{3}\] \[{{K}_{P}}={{\left( \frac{2P}{3} \right)}^{2}}\times \frac{P}{3}=\frac{4{{P}^{3}}}{27}\] Given \[{{K}_{P}}=2.9\times {{10}^{-5}}\] \[\therefore \]\[2.9\times {{10}^{-5}}=\frac{4{{P}^{3}}}{27}\] \[{{P}^{3}}=\frac{2.9\times {{10}^{-5}}\times 27}{4}\] \[P={{\left( \frac{2.9\times {{10}^{-5}}\times 27}{4} \right)}^{{}^{1}/{}_{3}}}=5.82\times {{10}^{-2}}atm\]


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