Correct Statements Regarding Properties and Reactions of Alkyl Halides

To determine the correct statements regarding alkyl halides ($\text{R}-\text{X}$), let us analyze each statement individually:

1. Statement A: Alcohol being less polar solvent as compared to water, alcoholic $\text{KOH}$ favours elimination reaction with $\text{R}-\text{X}$.

   • Alcohol is less polar than water. In an alcoholic medium, potassium hydroxide ($\text{KOH}$) reacts to form alkoxide ions ($\text{RO}^-$), which are stronger bases compared to hydroxide ions ($\text{OH}^-$) in an aqueous medium. Strong bases favor $\beta$-elimination (E2 mechanism) over nucleophilic substitution. Thus, Statement A is correct.

2. Statement B: Order of reactivity towards $\text{S}_\text{N}1$ mechanism is $\text{C}_6\text{H}_5-\text{CH}_2-\text{Cl} > \text{C}_6\text{H}_5-\text{CHCl}-\text{C}_6\text{H}_5$.

   • The rate of an $\text{S}_\text{N}1$ reaction depends on the stability of the intermediate carbocation:
     • $\text{C}_6\text{H}_5-\text{CH}_2-\text{Cl}$ forms the benzyl carbocation ($\text{C}_6\text{H}_5-\overset{+}{\text{C}}\text{H}_2$), stabilized by resonance with one phenyl ring.
     • $\text{C}_6\text{H}_5-\text{CHCl}-\text{C}_6\text{H}_5$ forms the diphenylmethyl carbocation ($\text{C}_6\text{H}_5-\overset{+}{\text{C}}\text{H}-\text{C}_6\text{H}_5$), stabilized by resonance with two phenyl rings.
   • Since the diphenylmethyl carbocation is more stable than the benzyl carbocation, the correct reactivity order towards $\text{S}_\text{N}1$ is: $\text{C}_6\text{H}_5-\text{CHCl}-\text{C}_6\text{H}_5 > \text{C}_6\text{H}_5-\text{CH}_2-\text{Cl}$
   • Thus, Statement B is incorrect.

3. Statement C: Non substituted aryl halides exhibit properties similar to alkyl halides.

   • Aryl halides are significantly less reactive towards nucleophilic substitution compared to alkyl halides because:
     • The $\text{C}-\text{X}$ bond acquires partial double bond character due to resonance with the aromatic ring.
     • The carbon atom bonded to the halogen is $sp^2$ hybridized (more electronegative), making cleavage of the $\text{C}-\text{X}$ bond difficult.
   • Therefore, non-substituted aryl halides do not exhibit properties similar to alkyl halides, making Statement C incorrect.

4. Statement D: Vinyl chloride is an example of haloalkene and allyl chloride is an example of haloalkyne.

   • Vinyl chloride ($\text{CH}_2=\text{CH}-\text{Cl}$) is a haloalkene.
   • Allyl chloride ($\text{CH}_2=\text{CH}-\text{CH}_2-\text{Cl}$) contains a double bond and is also a haloalkene, not a haloalkyne (which would contain a triple bond).
   • Thus, Statement D is incorrect.

5. Statement E: $\text{R}-\text{Cl}$ can be prepared by reacting $\text{R}-\text{OH}$ with $\text{SOCl}_2$ but $\text{Ar}-\text{Cl}$ cannot be prepared by reacting $\text{Ar}-\text{OH}$ with $\text{SOCl}_2$.

   • Alkyl chlorides ($\text{R}-\text{Cl}$) are prepared efficiently by reacting alcohols ($\text{R}-\text{OH}$) with thionyl chloride ($\text{SOCl}_2$).
   • However, in phenols ($\text{Ar}-\text{OH}$), the $\text{C}-\text{O}$ bond has partial double bond character due to resonance, making it extremely difficult to cleave. Thus, $\text{Ar}-\text{Cl}$ cannot be prepared by reacting $\text{Ar}-\text{OH}$ with $\text{SOCl}_2$.
   • Thus, Statement E is correct.

Comparing with the given choices, statements A and E Only are correct.

Correct Answer: C (A and E Only)