101.
Which of the carbon atoms present in the molecule given below are asymmetric?
A
(i), (ii), (iii) , (iv)
B
(ii), (iii)
C
(i), (iv)
D
(i), (ii), (iii)
Answer :
(ii), (iii)
102.
In the following sequence of reactions, which is incorrect
\[C{{H}_{2}}=CH-CH=C{{H}_{2}}\xrightarrow[{{80}^{\circ }}C]{HBr}A\xrightarrow{HBr}B\xrightarrow{Mg}C\]
A
$$A\,\,{\text{is}}\,\,C{H_3} - CH = CH - C{H_2}Br$$
B
$$B\,\,{\text{is}}\,\,C{H_3}CHBr - C{H_2} - C{H_2} - Br$$
C
$$C\,\,{\text{is cyclopropyl methane}}$$
D
$$\eqalign{
& B\,\,{\text{on}}\,\,{S_N}2\,\,{\text{with aqueous }}NaOH\,\,{\text{gives}} \cr
& C{H_3}CHOH.C{H_2}C{H_2}Br\,\,{\text{and not}} \cr
& C{H_3}CHBr.C{H_2}C{H_2}OH \cr} $$
Answer :
$$\eqalign{
& B\,\,{\text{on}}\,\,{S_N}2\,\,{\text{with aqueous }}NaOH\,\,{\text{gives}} \cr
& C{H_3}CHOH.C{H_2}C{H_2}Br\,\,{\text{and not}} \cr
& C{H_3}CHBr.C{H_2}C{H_2}OH \cr} $$
If $$B$$ reacts by $${S_N}2$$ mechanism, $$Br$$ on $${1^ \circ }$$ carbon must be replaced by $$O{H^ - }$$ to give $$C{H_3}CHBr - C{H_2} - C{H_2}OH.$$ 103. $$10\,g$$ mixture of iso-butane and iso-butene requires $$20\,g$$ of $$B{r_2}$$ $$\left( {{\text{in}}\,CC{l_4}} \right)$$ for complete addition. If $$10\,g$$ of the mixture is catalytically hydrogenated and the entire alkane is monobrominated in the presence of light at $${127^ \circ }C,$$ how much of it would be formed? ( Atomic weight of bromine = 80 )
A
24.21$$\,g$$
B
20.0$$\,g$$
C
30.0$$\,g$$
D
12$$\,g$$
Answer :
24.21$$\,g$$
104. Which of the following alkyl halides will undergo $${S_N}1$$ reaction most readily?
A
$${\left( {C{H_3}} \right)_3}C - F$$
B
$${\left( {C{H_3}} \right)_3}C - Cl$$
C
$${\left( {C{H_3}} \right)_3}C - Br$$
D
$${\left( {C{H_3}} \right)_3}C - I$$
Answer :
$${\left( {C{H_3}} \right)_3}C - I$$
heat favours elimination. 106. Which of the following alkyl halides is hydrolysed by $${S_N}1$$ mechanism?
A
$$C{H_3}Cl$$
B
$$C{H_3}C{H_2}Cl$$
C
$$C{H_3}C{H_2}C{H_2}Cl$$
D
$${\left( {C{H_3}} \right)_3}CCl$$
Answer :
$${\left( {C{H_3}} \right)_3}CCl$$
107.
Consider the following reaction and identify $$X$$ and $$Y$$
\[C{{H}_{3}}C{{H}_{2}}C{{H}_{2}}I\xrightarrow{alc.\,KOH}\] \[X\xrightarrow{B{{r}_{2}}}Y\]
A
(a)
B
(b)
C
(c)
D
(d)
Answer :
(a)
108.
Which of the following compounds will give racemic mixture on nucleophilic substitution by $$O{H^ - }$$ ion?
\[\begin{align}
& \left( \text{i} \right)C{{H}_{3}}\underset{\begin{smallmatrix}
|\,\,\,\,\, \\
{{C}_{2}}{{H}_{5}}
\end{smallmatrix}}{\mathop{-CH-}}\,Br \\
& \left( \text{ii} \right)C{{H}_{3}}\underset{\begin{smallmatrix}
| \\
\,\,\,\,\,{{C}_{2}}{{H}_{5}}
\end{smallmatrix}}{\overset{\begin{smallmatrix}
\,\,Br \\
|
\end{smallmatrix}}{\mathop{-C-}}}\,C{{H}_{3}} \\
& \left( \text{iii} \right)C{{H}_{3}}\underset{\begin{smallmatrix}
|\,\,\,\,\, \\
{{C}_{2}}{{H}_{5}}
\end{smallmatrix}}{\mathop{-CH-}}\,C{{H}_{2}}Br \\
\end{align}\]
A
(i)
B
(i), (ii), (iii)
C
(ii), (iii)
D
(i), (iii)
Answer :
(i)
109.
Match the column I with column II and mark the appropriate choice.
Column I
Column II
a.
\[C{H_3}{\left( {C{H_2}} \right)_3}OH\xrightarrow[{{H_2}S{O_4},\Delta }]{{NaBr}}\]
1.
\[C{H_3}CH\left( {Br} \right){\left( {C{H_2}} \right)_2}C{H_3}\]
b.
\[{\left( {C{H_3}} \right)_3}COH\xrightarrow[{{\text{room}}\,{\text{temp}}{\text{.}}}]{{{\text{Conc}}.\,HCl}}\]
2.
\[C{H_3}C{H_2}C{H_2}Cl\]
c.
\[C{H_3}CH\left( {OH} \right){\left( {C{H_2}} \right)_2}C{H_3}\xrightarrow{{PB{r_3}}}\]
3.
\[{\left( {C{H_3}} \right)_3}CCl\]
d.
\[C{H_3}C{H_2}C{H_2}OH\xrightarrow{{SOC{l_2}}}\]
4.
\[C{H_3}{\left( {C{H_2}} \right)_3}Br\]
A
a - 4, b - 3, c - 1, d - 2
B
a - 4, b - 3, c - 2, d - 1
C
a - 3, b - 4, c - 1, d - 2
D
a - 3, b - 4, c - 2, d - 1
Answer :
a - 4, b - 3, c - 1, d - 2
110. The total number of acyclic isomers including the stereoisomers with the molecular formula $${C_4}{H_7}Cl$$
A
11
B
12
C
9
D
10
Answer :
12
