In which pairs, the first ion is more stable than the second?

Stability pair A components for Q30
The prompt displays visual comparisons of organic ionic species to judge the relative stability within pairs (A), (B), (C), and (D).
Stability pair A components for Q30
The prompt displays visual comparisons of organic ionic species to judge the relative stability within pairs (A), (B), (C), and (D).
Stability pair A components for Q30
The prompt displays visual comparisons of organic ionic species to judge the relative stability within pairs (A), (B), (C), and (D).
Stability pair A components for Q30
The prompt displays visual comparisons of organic ionic species to judge the relative stability within pairs (A), (B), (C), and (D).
Stability pair A components for Q30
The prompt displays visual comparisons of organic ionic species to judge the relative stability within pairs (A), (B), (C), and (D).
Stability pair A components for Q30
The prompt displays visual comparisons of organic ionic species to judge the relative stability within pairs (A), (B), (C), and (D).

Solution & Explanation

### Related Formula textStability propto textDelocalization of charge via resonance, mesomeric, and back-bonding effects ### Core Logic Evaluating each specific structural pair: - **Pair (A):** The first carbocation is stabilized by strong +M back-bonding from the methoxy (-OMe) oxygen lone pair, making it significantly more stable than the second. - **Pair (B):** The first carbanion is strongly stabilized by the -M and -I electronic effects of the nitro (-NO_2) group situated at the ortho position, whereas a carbocation in that spot would be destabilized. Thus, the first ion is more stable. - **Pair (C):** The second cation has extended allylic resonance stabilization, meaning the first is less stable. - **Pair (D):** Cation with -OMe backbonding is more stable than tertiary aliphatic carbocation, making the first less stable than the second. Thus, only in **(A) & (B)** is the first ion more stable than the second. ### Pattern Recognition Back-bonding from an adjacent oxygen lone pair always triumphs over standard inductive or hyperconjugative alkyl stability templates. For carbanions, ensure electron-withdrawing groups like -NO_2 match the sign of the charge. ### Evaluation Rubric / Model Answer null ### Chapter Mix Class 11 Chemistry: Some Basic Principles of Organic Chemistry
Carbocation and Carbanion Stability
The prompt displays visual comparisons of organic ionic species to judge the relative stability within pairs (A), (B), (C), and (D).

More Some Basic Principles of Organic Chemistry 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%)