51. The reagents which can be used to distinguish acetophenone from benzophenone is (are)
A
2, 4 - dinitrophenyl hydrazine
B
aqueous solution of $$NaHS{O_3}$$
C
Benedict reagent
D
$${I_2}$$ and $$N{a_2}C{O_3}$$
Answer :
$${I_2}$$ and $$N{a_2}C{O_3}$$
unit, is treated with $${I_2}$$ and $$N{a_2}C{O_3}$$ it forms yellow precipitate of $$CH{I_3}$$ whereas benzophenone does not give this test.Acetophenons gives iodoform test due to presence of $$ - COC{H_3}$$ group. 52. What are the correct steps to convert acetaldehyde to acetone?
A
$${C_2}{H_5}MgBr,{H_2}O,{\text{Oxidation}}$$
B
$${\text{Oxidation}},Ca{\left( {OH} \right)_2},{\text{Heat}}$$
C
$${\text{Reduction, }}KCN{\text{, Hydrolysis }}$$
D
$${\text{Oxidation}},{C_2}{H_5}ONa,{\text{Heat}}$$
Answer :
$${\text{Oxidation}},Ca{\left( {OH} \right)_2},{\text{Heat}}$$
and $$B$$ is $$LiAl{H_4}.$$
54.
In the following reaction sequence, the correct structures of $$E,$$ $$F$$ and $$G$$ are
\[\left[ * \right.\text{implies}{{\,}^{13}}C\,\,\left. \text{labelled carbon} \right)\]
A
B
C
D
Answer :
55. Which of the following will not give aldol condensation?
A
Phenyl acetaldehyde
B
2-Methylpentanal
C
Benzaldehyde
D
1-Phenylpropanone
Answer :
Benzaldehyde
56.
The major product of the following reaction is :
\[C{{H}_{3}}CH=CHC{{O}_{2}}C{{H}_{3}}\xrightarrow{LiAl{{H}_{4}}}\]
A
$$C{H_3}C{H_2}C{H_2}C{O_2}C{H_3}$$
B
$$C{H_3}CH = CHC{H_2}OH$$
C
$$C{H_3}C{H_2}C{H_2}C{H_2}OH$$
D
$$C{H_3}C{H_2}C{H_2}CHO$$
Answer :
$$C{H_3}CH = CHC{H_2}OH$$
57.
What is the product of the following reaction ?
\[\xrightarrow[DMSO]{{{\left( {{C}_{6}}{{H}_{5}} \right)}_{3}}{{P}^{+}}-\,\ddot{C}H_{2}^{-}}\]
A
2 - methyl - 1- pentene
B
4 - methyl - 1- pentene
C
2 - methyl - 2- propyloxirane
D
1 - pentene
Answer :
2 - methyl - 1- pentene
58. Ethyl acetate is obtained when methylmagnesium iodide reacts with
A
ethyl formate
B
ethyl chloroformate
C
acetyl chloride
D
carbon dioxide
Answer :
ethyl chloroformate
60. The best method to purify impure acetone is
A
\[C{{H}_{3}}COC{{H}_{3}}+HCl\to \] \[C{{H}_{3}}\underset{\begin{smallmatrix}
| \\
Cl
\end{smallmatrix}}{\overset{\begin{smallmatrix}
\,\,\,\,OH \\
|
\end{smallmatrix}}{\mathop{-C-}}}\,C{{H}_{3}}\xrightarrow{\text{heat}}\] \[C{{H}_{3}}COC{{H}_{3}}\]
B
\[C{{H}_{3}}COC{{H}_{3}}+NaHS{{O}_{3}}\to \] \[C{{H}_{3}}\underset{\begin{smallmatrix}
| \\
\,\,\,C{{H}_{3}}
\end{smallmatrix}}{\overset{\begin{smallmatrix}
\,\,\,\,OH \\
|
\end{smallmatrix}}{\mathop{-C-}}}\,S{{O}_{3}}Na\xrightarrow{N{{a}_{2}}C{{O}_{3}}}\] \[C{{H}_{3}}COC{{H}_{3}}\]
C
\[C{{H}_{3}}COC{{H}_{3}}+HCN\to \] \[C{{H}_{3}}\underset{\begin{smallmatrix}
| \\
\,CN
\end{smallmatrix}}{\overset{\begin{smallmatrix}
\,\,\,\,OH \\
|
\end{smallmatrix}}{\mathop{-C-}}}\,C{{H}_{3}}\xrightarrow{HOH}\] \[C{{H}_{3}}COC{{H}_{3}}\]
D
\[C{{H}_{3}}COC{{H}_{3}}+{{H}_{2}}S{{O}_{4}}\to \] \[\underset{\begin{smallmatrix}
| \\
\,\,\,\,\,\,\,\,\,OS{{O}_{3}}H
\end{smallmatrix}}{\overset{\begin{smallmatrix}
\,\,\,\,OH \\
|
\end{smallmatrix}}{\mathop{C{{H}_{3}}-C-C{{H}_{3}}}}}\,\xrightarrow{\text{heat}}C{{H}_{3}}COC{{H}_{3}}\]
Answer :
\[C{{H}_{3}}COC{{H}_{3}}+NaHS{{O}_{3}}\to \] \[C{{H}_{3}}\underset{\begin{smallmatrix}
| \\
\,\,\,C{{H}_{3}}
\end{smallmatrix}}{\overset{\begin{smallmatrix}
\,\,\,\,OH \\
|
\end{smallmatrix}}{\mathop{-C-}}}\,S{{O}_{3}}Na\xrightarrow{N{{a}_{2}}C{{O}_{3}}}\] \[C{{H}_{3}}COC{{H}_{3}}\]