Alkyl and Aryl Halide MCQ Questions & Answers in Organic Chemistry | Chemistry

Alkyl fluorides are more conveniently prepared by heating suitable chloro - or bromo - alkanes with organic fluorides such as $$As{F_3},Sb{F_3},Co{F_2},AgF,H{g_2}{F_2}$$       etc.
This reaction is called Swarts reaction.
$$\eqalign{ & C{H_3}Br + AgF \to C{H_3}F + AgBr \cr & 2C{H_3}C{H_2}Cl + H{g_2}{F_2} \to 2C{H_3}C{H_2}F + H{g_2}C{l_2} \cr} $$

$$DDT$$  is a non-biodegradable pollutant.

$$C{H_3}OH + {C_6}{H_5}MgBr \to C{H_3}O.MgBr + {C_6}{H_6}$$

Since $${S_N}1$$  reactions involve the formation of carbocation as intermediate in the rate determining step, more is the stability of carbocation higher will be reactivity of alkyl halides towards $${S_N}1$$  route. Now we know that stability of carbocations follows the order : $${3^ \circ } > {2^ \circ } > {1^ \circ },$$    so $${S_N}1$$  reactivity should also follow the same order.
$${3^ \circ } > {2^ \circ } > {1^ \circ } > $$    Methyl ( $${S_N}1$$  reactivity )

\[\underset{n-\text{Propyl bromide}}{\mathop{C{{H}_{3}}-C{{H}_{2}}-C{{H}_{2}}Br}}\,\xrightarrow[-HBr]{\text{ethanolic}\,\text{KOH}}C{{H}_{3}}-\underset{\text{Propene}}{\mathop{CH}}\,=C{{H}_{2}}\]
Further dehydrohalogenation of \[C{{H}_{3}}CH=C{{H}_{2}}\]    can be done only by strong base like \[NaN{{H}_{2}}.\]

In Corey House synthesis of alkanes alkyl halide react with lithium dialkyl cuprate
$$R'X + Li{R_2}Cu \to R' - R + RCu + LiX$$

$$RCl + NaOH\left( {aq} \right) \to ROH + NaCl$$
It is an example of nucleophilic substitution reaction.

Gammexane is benzene hexachloride

$$C{H_3}$$  is $$o/p$$  - directing group, thus electrophilic substitution reaction of toluene