question_answer

When alcohol reacts with concentrated \[{{H}_{2}}S{{O}_{4}}\]intermediate compound formed is            [AFMC 2005]

A)                 Carbonium ion 

B)                 Alkoxy ion

C)                 Alkyl hydrogen sulphate              

D)                 None of these

Correct Answer: A

Solution :

           \[-\underset{\underset{H}{\mathop{|}}\,}{\overset{|}{\mathop{C}}}\,\,\,\,\,\,-\underset{\underset{\,\,\,\,OH}{\mathop{|}}\,}{\overset{|}{\mathop{C}}}\,-\]  \[-\underset{\underset{\underset{\begin{smallmatrix}  \text{Protonated} \\  \,\,\,\,\,\text{alcohol} \end{smallmatrix}}{\mathop{H}}\,}{\mathop{|}}\,}{\overset{|}{\mathop{C}}}\,-\underset{\underset{{}^{+}O{{H}_{2}}}{\mathop{|}}\,}{\overset{|}{\mathop{C}}}\,-\] In all cases intermediate is carbonium ion, and there may be 1, 2-hydride or 1, 2-methyl shift to form more stable carbonium ion.