i) DDT: DDT can be prepared by heating a mixture of chlorobenzene with chloral (Trichloro acetaldehyde) in the presence of con. H₂SO₄,

ii) Chloroform :The reaction of methane with excess of chlorine in the presence of sunlight will give carbon tetrachloride as the major product.
\(\underset { Methane }{ { CH }_{ 4 }+4C{ l }_{ 2 }\overset { h\gamma }{ \longrightarrow } } +\underset { Carbon \ tetrachloride }{ 4HCl } \)
iii) Bipheenyl :
\(\underset { Chlorobenzene }{ { C }_{ 6 }{ H }_{ 5 }Cl } +2Na+Cl-{ C }_{ 6 }{ H }_{ 5 }\overset { Ether }{ \longrightarrow } \underset { Biphenyl }{ { C }_{ 6 }{ H }_{ 5 }-{ C }_{ 6 }{ H }_{ 5 }+2NaCl } \)
iv) Chloropicrin : Chloroform reacts with nitric acid to form chloropicrin.(Trichloro nitro methane)
\(\underset { Chloroform }{ { CH }_{ 3 }+HN{ O }_{ 3 }\overset { \triangle }{ \longrightarrow } } \underset { Chloropicrin }{ C{ Cl }_{ 3 }N{ O }_{ 2 }+{ H }_{ 2 }O } \)
v) Freon-12 :Freon - 12 is prepared by the action of hydrogen fluoride on carbon tetrachloride in . the presence of catalylic amount of antimony pentachloride. is is called swartz reaction
\(\underset { Carbontetrachloridew }{ { CCl }_{ 3 }+2HF\overset { SbC{ l }_{ 5 } }{ \longrightarrow } } \underset { Freon-12 }{ 2HC{ l }+CCl_{ 2 }F_{ 2 } } \)

i) Acetic acid: Solid carbon dioxide reacts with Grignard reagent to form addition product which on hydrolysis yields carboxylic acids.

ii) Acetone :
\(\underset { Iodomethane }{ { CH }_{ 3 }-I+Mg } \overset { dryether }{ \longrightarrow } \underset { Methyl \ magnesium \ iodide }{ { CH }_{ 3 }MgI } \)
iii) Ethyl acetate: Ethy1chloroformate reacts with Grignard reagent to form esters.

iv) Iso propyl alcohol : Aldehydes other than formaldehyde, react with Grignard reagent to give addition product which on hydrolysis yields secondary alcohol.

v) Methyl cyanide : Grignard reagent reacts with cyanogen chloride to from alkyl cyanide

The rate of the following SN₁ reaction depends upon the concentration of alkyl halide (RX) and is independent of the concentration of the nucleophile (OH-).
Hence Rate of the reaction = k [alkyl halide]
SN₁ reaction mechanism by taking a reaction between tertiary butyl bromide with aqueous KOH.
\({ CH }_{ 3 }-\overset { \underset { | }{ { CH }_{ 3 } } }{ \underset { \overset { | }{ { CH }_{ 3 } } }{ C } } -Br\overset { { OH }^{ - }(aq) }{ \underset { -Br }{ \longrightarrow } } { CH }_{ 3 }-\overset { \underset { | }{ { CH }_{ 3 } } }{ \underset { \overset { | }{ { CH }_{ 3 } } }{ C } } -OH\)
Tert-Butyl bromide                           Tert-Butyl alcohol
This reaction takes place in two steps as shown below
Step-1 Formation of carbocation :
The polar C - Br bond breaks forming a carbocation and bromide ion. is step is slow and hence it is the rate determining step

The carbocation has 2 equivalent lobes of the vacant 2p orbital, so it can react equally rapidly from either face
Ste - 2
The nucleophile immediately reacts with the carbocation. This step is fast and hence does not affect the rate of the reactions.

As shown above, the nucleophilic reagent OH^- can attack carbocation from both the sides.

Freons (CFC): The chloro uoro derivatives of methane and ethane are called freons.
Uses:
(i) Freons are a used as refrigerants in refrigerators and air conditioners. 
(ii) It is used as a propellant for aerosols and foams
(iii) It is used as propellant for foams to spray out deodorants, shaving creams, and insecticides

a) The product formed is ethylmagnesium iodide (Grignard reagent)
\({ C }_{ 2 }{ H }_{ 5 }+Mg\overset { dryether }{ \rightarrow } { { C }_{ 2 }H }_{ 5 }Mgl\)
                                 Ethyl magnesium iodide
b) The Grignard carbon is highly basic and reacts with acidic protons of polar solvents like water to form an alkani so all reagents should be pure and dry.