Question

Given below are two statements: 
Statement I: The conversion proceeds well in a less polar medium. \[ {CH}_3{CH}_2{CH}_2{CH}_2{Cl} \xrightarrow{{HO}^-} {CH}_3{CH}_2{CH}_2{CH}_2{OH} + {Cl}^- \] Statement II: The conversion proceeds well in a more polar medium. \[ {CH}_3{CH}_2{CH}_2{CH}_2{Cl} \xrightarrow{{R}_3{N}} {CH}_3{CH}_2{CH}_2{CH}_2{NH}_2 + {Cl}^- \] In the light of the above statements, choose the correct answer from the options given below:

• A. Both statement I and statement II are true
• B. Both statement I and statement II are false
• C. Statement I is false but statement II is true
• D. Statement I is true but statement II is false

Hint:

In SN2 reactions, the choice of solvent is crucial. Less polar solvents are ideal for reactions with strong nucleophiles, while more polar solvents favor the reaction by stabilizing the leaving group.

Answer 1

The Correct Option is A

To evaluate the given statements about organic reactions involving conversion of \({CH}_3{CH}_2{CH}_2{CH}_2{Cl}\), let's examine each one:

1. Statement I: The conversion proceeds well in a less polar medium. \[ {CH}_3{CH}_2{CH}_2{CH}_2{Cl} \xrightarrow{{HO}^-} {CH}_3{CH}_2{CH}_2{CH}_2{OH} + {Cl}^- \]
   • This reaction is a nucleophilic substitution reaction where hydroxide ion (\(HO^-\)) attacks the alkyl chloride to form butanol.
   • In SN2 reactions like this one, less polar solvents are preferred because polar solvents can stabilize the nucleophile (here, \(HO^-\)), making it less reactive.
   • Thus, Statement I is accurate as the reaction proceeds better in a less polar medium, supporting the SN2 mechanism.
2. Statement II: The conversion proceeds well in a more polar medium. \[ {CH}_3{CH}_2{CH}_2{CH}_2{Cl} \xrightarrow{{R}_3{N}} {CH}_3{CH}_2{CH}_2{CH}_2{NH}_2 + {Cl}^- \]
   • This transformation involves an amine catalyst (\({R}_3N\)) facilitating the reaction.
   • Polar solvents can stabilize the reactants and intermediates involving polar reactants, such as those with amines, which aids in the reaction progress.
   • Hence, a more polar medium facilitates this reaction, making Statement II correct.

After understanding both reactions, we can conclude that:

Correct Answer: Both statement I and statement II are true.

Answer 2

Freezing point depression occurs when a solute is added to a solvent, lowering its freezing point.
The correct graph shows the vapor pressure curve of the solution below that of the pure solvent, with the freezing point of the solution occurring at a lower temperature.
The correct representation is \( \text{Option (3)} \), where the freezing point depression (\( \Delta T_f \)) is clearly shown, with the solution curve below the solvent curve.
Thus, the correct answer is: \( \boxed{(3)} \).