Consider the following compound (X) beginarrayc mathrm I \\ mathrm H - mathrm C equiv mathrm C - mathrm C H _ 2 - mathrm C H - mathrm C H _ 3 \\ mathrm I \\ mathrm C H _ 3 endarray The most stable and least stable carbon radicals, respectively, produced by homolytic cleavage of corresponding mathrmC - H bond are :

Solution & Explanation

### Related Formula Free radical stability structural hierarchy sequence: textResonance Stabilized (Propargyl/Allyl) > 3^circ > 2^circ > 1^circ > textVinylic/Alkyne Center ### Core Logic Let's analyze individual cleavage points across the carbon backbone skeleton: * **Position II** yields a propargyl intermediate radical directly adjacent to the alkyne bond. This allows strong resonance stabilization across the pi system, making it the most stable radical position. * **Position I** places the radical directly on an mathrmsp-hybridized carbon center. The high electronegativity of mathrmsp orbitals tightly holds the unpaired electron, making homolytic cleavage extremely difficult and rendering this intermediate the least stable radical position.
Free Radical Stability
Free Radical Stability
### Step 1: Verdict Therefore, the most stable and least stable positions are II and I, respectively. ### Pattern Recognition Radicals located on mathrmsp carbons (vinylic/alkynic) are highly unstable due to poor orbital overlap, while positions next to triple bonds (propargylic) are exceptionally stable due to active resonance delocalization. ### Evaluation Rubric / Model Answer null ### Chapter Mix Class 11 Chemistry: Organic Chemistry - Some Basic Principles and Techniques

More Organic Chemistry - Some Basic Principles and Techniques Previous-Year Questions — Page 16

Q72 jee_main_2024_31_jan_morning Purification Methods
'Adsorption' principle is used for which of the following purification method?
  • A. textExtraction
  • B. textChromatography
  • C. textDistillation
  • D. textSublimation

Solution

### Core Logic The fundamental principle used in chromatography (such as column chromatography or thin-layer chromatography) is adsorption. Different components of a mixture are adsorbed to different extents on an adsorbent stationary phase. ### Evaluation Rubric / Model Answer null ### Chapter Mix Class 11 Chemistry: Organic Chemistry - Some Basic Principles and Techniques
Q80 jee_main_2024_31_jan_morning Purification Methods
Match List I with List II
LIST-I (Technique)LIST-II (Application)
A. DistillationI. Separation of glycerol from spent-lye
B. Fractional distillationII. Aniline - Water mixture
C. Steam distillationIII. Separation of crude oil fractions
D. Distillation under reduced pressureIV. Chloroform-Aniline
Choose the correct answer from the options given below:
  • A. textA-IV, B-I, C-II, D-III
  • B. textA-IV, B-III, C-II, D-I
  • C. textA-I, B-II, C-IV, D-III
  • D. textA-II, B-III, C-I, D-IV

Solution

### Core Logic (A) Simple distillation is used to separate a mixture of miscible liquids with a sufficiently large difference in their boiling points, such as chloroform and aniline. (A rightarrow IV) (B) Fractional distillation is used to separate crude oil fractions. (B rightarrow III) (C) Steam distillation is used to separate steam-volatile substances that are immiscible with water, like an aniline-water mixture. (C rightarrow II) (D) Distillation under reduced pressure is used for liquids that decompose at or below their normal boiling points, like separating glycerol from spent lye. (D rightarrow I) ### Evaluation Rubric / Model Answer null ### Chapter Mix Class 11 Chemistry: Organic Chemistry - Some Basic Principles and Techniques
Rankbit System
JEE Physics: Waves (+15.5%) | Electrostatics: Concentric Shells (-29.7%) | Modern Physics: Photoelectric Clones (+34.2%) | Mathematics: Definite Integrals (+18.1%) | Chemistry: Coordination Splitting (-11.4%) | JEE Physics: Waves (+15.5%) | Electrostatics: Concentric Shells (-29.7%) | Modern Physics: Photoelectric Clones (+34.2%) | Mathematics: Definite Integrals (+18.1%) | Chemistry: Coordination Splitting (-11.4%)