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KVPY Sample Paper KVPY Stream-SX Model Paper-2

  • question_answer
    On being placed in water, sodium peroxide not only produces an alkaline solution but also some bubbles. If we assume that the peroxide ion picks up two protons from water to produce a compound that can be seen as the disproportion. Using the above information complete the following equation. \[\begin{align}   & N{{a}_{2}}{{O}_{2}}(s)\,+{{H}_{2}}O(1)\xrightarrow{{}}(A)+(B) \\  & (A)\,and\,(B)\,are \\ \end{align}\]

    A)  \[{{H}_{2}}{{O}_{2\,}}and\,NaOH\]   

    B) \[{{H}_{2}}O\,and\,{{O}_{2}}\]

    C) \[NaOH\,and\,{{O}_{2}}\]        

    D) \[N{{a}_{2}}O\,and\,NaOH\]

    Correct Answer: C

    Solution :

    [c] Form the given information, we can see that the reaction proceeds via formation of \[{{H}_{2}}{{O}_{2}}\](which is diabasic conjugated acid of peroxide ion) \[{{H}_{2}}{{O}_{2}}\]then disproportionates into water any oxygen. \[N{{a}_{2}}{{O}_{2}}(s)+{{H}_{2}}O(1)\xrightarrow{{}}2NaOH(aq)+{{H}_{2}}{{O}_{2}}(aq)\]\[{{H}_{2}}{{O}_{2}}(aq)\xrightarrow{{}}{{H}_{2}}O\left( 1 \right)+\frac{1}{2}{{O}_{2}}(g)\] Thus overall reaction is \[N{{a}_{2}}{{O}_{2}}(s)+{{H}_{2}}O(1)\xrightarrow{{}}2NaOH(aq)+\frac{1}{2}{{O}_{2}}(g)\]


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