Electron Displacement Effects

Step 1: Concept
The inductive effect is a permanent effect involving -bonds.
Step 2: Analysis
It occurs due to the electronegativity difference between atoms, causing a partial shifting or displacement of -electron density along the chain.
Step 3: Conclusion
It specifically involves the displacement of -electrons.
Final Answer: (D)

Step 1: Buoyancy
When immersed in water, objects experience an upward buoyant force equal to the weight of water displaced.
Step 2: Density Comparison
Steel is much denser than aluminium. For equal weights in water, the volumes and initial masses must differ.
Step 3: Atomic Weight
Atomic weight of Iron (Steel) is 56 and Aluminium is 27. Based on their relative densities and the given equilibrium in water, the aluminium piece weighs approximately half as much as the steel piece in air.
Final Answer: (a)

Step 1: Concept
Electron-withdrawing groups (like ) increase the acidity of benzoic acid.
Step 2: Analysis
- Ortho-substituted benzoic acids are generally more acidic than benzoic acid due to the "ortho effect" (steric inhibition of resonance). Thus, II is the most acidic.
Step 3: Substituent Position
- The and effects of work together at the para position (III). - Only the effect works at the meta position (IV).
Step 4: Conclusion
The correct order is: (II>III>IV>I).
Final Answer: (D)

Step 1: Concept
The inductive effect is a permanent effect where a substituent group causes the polarization of a molecule through -bonds.
Step 2: Analysis
Unlike resonance or electromeric effects, the inductive effect does not involve the movement of -electrons or the complete delocalisation of electrons.
Step 3: Conclusion
It involves only the partial displacement of -electrons toward the more electronegative atom in a chain.
Final Answer: (B)

Step 1: Structure
Carbanions are negatively charged species where carbon has 8 valence electrons (6 from bonds + 2 in lone pair).
Step 2: Magnetic Property
Since all 8 electrons are paired (even number), carbanions are diamagnetic, not paramagnetic.
Step 3: Hybridization
The central carbon is typically hybridised (pyramidal geometry).
Step 4: Formation
They are formed by the heterolytic cleavage of a covalent bond where carbon takes both electrons.
Final Answer: (C)

Step 1: Concept
Acidity depends on the stability of the conjugate base formed after losing a proton ( ).
Step 2: Analysis
When phenol loses a proton, it forms a phenoxide ion.
Step 3: Conclusion
The phenoxide ion is resonance stabilized, which makes phenol more acidic.
Final Answer: (D)

Concept: Hyperconjugation = to electron delocalization

Step 1: In hyperconjugation, electrons from (C–H) bond are involved.

Step 2: These electrons delocalize into adjacent -system or empty orbital.

Step 3: This leads to stabilization of molecule.

Step 4: Option (C) correctly describes delocalization.
Conclusion:
Correct definition = Option (C)