question_answer 47)

  In which of the following compounds, an element exhibits two different oxidation states? (a) \[N{{H}_{2}}OH\]                      (b) \[N{{H}_{4}}N{{O}_{3}}\]                       (c) \[{{N}_{2}}{{H}_{4}}\]                              (d) \[{{N}_{3}}H\]

Answer:

  (b)\[N{{H}_{4}}N{{O}_{3}},\] \[\underset{\begin{smallmatrix}  x\,+\,4\,=\,+\,1 \\  x\,=\,-3 \end{smallmatrix}}{\mathop{NH_{4}^{+}}}\,\]                   \[\underset{\begin{smallmatrix}  x\,-\,6\,=\,-1 \\  x\,=\,+5 \end{smallmatrix}}{\mathop{NO_{3}^{-}}}\,\] Thus, both nitrogen atoms are in different oxidation states.