question_answer 1)

  What is the correct order of decreasing stability of the following cations? \[C{{H}_{3}}-\underset{(I)}{\mathop{\overset{\oplus }{\mathop{CH}}\,}}\,-C{{H}_{3}}\]               \[C{{H}_{3}}-\underset{\text{(II)}}{\mathop{\overset{\oplus }{\mathop{CH}}\,}}\,-OC{{H}_{3}}\]      \[C{{H}_{3}}-\overset{\oplus }{\mathop{CH}}\,-\underset{(III)}{\mathop{C{{H}_{2}}}}\,-OC{{H}_{3}}\]            (a) II > I > III                        (b) II > III > I                        (c) III > I > II                        (d) I > II > III

Answer:

  (a)\[C{{H}_{3}}\to -\underset{\begin{smallmatrix}  Stabilized\,by\,weak\,+Ieffect \\  of\,the\,two\,C{{H}_{3}}groups \end{smallmatrix}}{\mathop{\underset{(I)}{\mathop{\overset{+}{\mathop{CH}}\,}}\,}}\,-\leftarrow C{{H}_{3}}\]