WB JEE Medical WB JEE Medical Solved Paper-2007

  • question_answer
    \[{{N}_{2}}\]and\[{{H}_{2}}\]in 1 : 3 molar ratio are heated in a closed container having a catalyst. When the following   equilibrium \[{{N}_{2}}(g)+3{{H}_{2}}(g)2N{{H}_{3}}(g)\] is attained, the total pressure is 10 atm and mole fraction of \[N{{H}_{3}}\] is 0.60. The equilibrium constant \[{{K}_{p}}\] for dissociation of \[N{{H}_{3}}\] is

    A)  \[1.333\text{ }at{{m}^{-2}}\]     

    B)  \[0.75\text{ }at{{m}^{2}}\]

    C)  \[0.75\text{ }at{{m}^{-2}}\]       

    D)  \[1.333\text{ }at{{m}^{2}}\]

    Correct Answer: B

    Solution :

                     \[{{N}_{2}}(g)+3{{H}_{2}}(g)2N{{H}_{3}}(g)\] Mole fraction of \[N{{H}_{3}}({{X}_{N{{H}_{3}}}})=0.6\] Mole fraction of \[{{N}_{2}}\]and \[{{H}_{2}}=1-0.6=0.4\] Total no. of mole of \[{{N}_{2}}\]and \[{{H}_{2}}=1+3=4\] Then, \[{{X}_{{{N}_{2}}}}=\frac{1}{4}\times 0.4=0.1\] \[{{X}_{{{H}_{2}}}}=\frac{3}{4}\times 0.4=0.3\] Partial pressure of \[{{N}_{2}}({{P}_{{{N}_{2}}}})=0.1\times 10=1\,\text{atm}\] Partial pressure of \[{{H}_{2}}({{P}_{{{H}_{2}}}})\] \[=0.3\times 10=3\,\text{atm}\] Partial pressure of \[N{{H}_{3}}\] \[({{P}_{N{{H}_{3}}}})\]             \[=0.6\times 10=6\,\text{atm}\] Dissociation of ammonia \[2N{{H}_{3}}{{N}_{2}}+3{{H}_{2}}\] \[{{K}_{P}}=\frac{{{P}_{{{N}_{2}}}}\times P_{{{H}_{2}}}^{3}}{P_{N{{H}_{3}}}^{2}}\] \[=\frac{1\times {{(3)}^{3}}}{{{(6)}^{2}}}\] \[=\frac{27}{36}=0.75\,\text{at}{{\text{m}}^{\text{2}}}\]


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