JCECE Engineering JCECE Engineering Solved Paper-2004

  • question_answer
    Which of the following alcohol give positive iodo form test?

    A)  Methanol          

    B)  Ethyl carbinol

    C)   Pentanol\[-3\]               

    D)   Methyl carbinol

    Correct Answer: D

    Solution :

    Key Idea: Iodoform test is given by alcohols which produce carbonyl compounds having \[C{{H}_{3}}CO\] group. (i)\[C{{H}_{3}}OH\xrightarrow{[O]}HCHO\], no\[C{{H}_{3}}CO\]group, no iodoform test. (ii)\[\underset{\begin{smallmatrix}  methyl \\  carbinol \end{smallmatrix}}{\mathop{{{C}_{2}}{{H}_{5}}OH}}\,\xrightarrow{[O]}C{{H}_{3}}CHO\], has \[C{{H}_{3}}CO\] group, gives iodoform test (iii)\[\underset{\begin{smallmatrix}  ethyl \\  carbinol \end{smallmatrix}}{\mathop{{{C}_{2}}{{H}_{5}}C{{H}_{2}}OH}}\,\xrightarrow{[O]}{{C}_{2}}{{H}_{5}}CHO\], no\[C{{H}_{3}}CO\] group no iodoform test. (iv)\[C{{H}_{3}}-C{{H}_{2}}-CH(OH)-C{{H}_{2}}-C{{H}_{3}}\xrightarrow{[O]}\]\[C{{H}_{3}}-C{{H}_{2}}-\overset{\begin{smallmatrix}  O \\  || \end{smallmatrix}}{\mathop{C}}\,-C{{H}_{2}}-C{{H}_{3}}\] No \[C{{H}_{3}}CO\] group, no iodoform test. \[\therefore \]Only methyl carbinol gives iodoform test.


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