How many compounds among the following compounds show inductive, mesomeric as well as hyperconjugation effects?
Correct Answer: 4
Approach Solution - 1
To determine how many compounds exhibit inductive, mesomeric, and hyperconjugation effects, we must analyze each compound:
- C6H5CH2OCH3:
- Inductive Effect: Yes, due to the electronegative oxygen.
- Mesomeric Effect: Yes, the benzene ring can participate in resonance.
- Hyperconjugation: No, as there are no adjacent C-H bonds to the carbon having a positive charge or double bond.
- C6H5CH2CH=CH2:
- Inductive Effect: Yes, due to σ-bond polarization.
- Mesomeric Effect: Yes, due to the benzene ring.
- Hyperconjugation: Yes, due to the adjacent double-bonded C-H bonds.
- C6H5CH2CH(NO2)CH3:
- Inductive Effect: Yes, nitro group is highly electronegative.
- Mesomeric Effect: No, the nitro group is not directly conjugated with the benzene ring.
- Hyperconjugation: Yes, due to C-H bonds adjacent to the benzene ring.
- C6H5CH2CH2Cl:
- Inductive Effect: Yes, Cl is electronegative.
- Mesomeric Effect: No, no conjugation with the benzene ring.
- Hyperconjugation: No significant hyperconjugation effect exists.
- C6H5NO2:
- Inductive Effect: Yes, the nitro group.
- Mesomeric Effect: Yes, nitro group conjugated with benzene.
- Hyperconjugation: No, lacks appropriate hydrogen atoms.
- C6H5CH=CHC6H5:
- Inductive Effect: Yes, due to polarizable π bonds.
- Mesomeric Effect: Yes, both benzene rings contribute.
- Hyperconjugation: Yes, due to C-H bonds adjacent to double bonds.
- C6H5CH(CH3)COCH3:
- Inductive Effect: Yes, due to CO group.
- Mesomeric Effect: Yes, CO group conjugates with benzene.
- Hyperconjugation: Yes, due to methyl groups.
- C6H11CH3:
- Inductive Effect: Yes, alkyl group polarization.
- Mesomeric Effect: No, cyclohexane ring doesn’t allow conjugation.
- Hyperconjugation: Yes, due to multiple C-H bonds.
Based on this analysis, the compounds that show all three effects are: C6H5CH2CH=CH2, C6H5CH=CHC6H5, C6H5CH(CH3)COCH3. There are 3 such compounds, which does not fit the specified range (4, 4). Thus, there may have been an error in the expected range.
Approach Solution -2
Step 1: Analyze each compound - Compound 1 (−OCH3 group attached): The −OCH3 group exhibits both inductive (−I) and mesomeric (+M) effects. However, hyperconjugation is not applicable here. Not included.
- Compound 2 (Alkene with −CH3): The −CH3 group shows inductive (+I) and hyperconjugation effects due to the presence of alpha hydrogens. Mesomeric effect is not present. Not included.
- Compound 3 (−NO2 group): The −NO2 group exhibits both −I (inductive) and −M (mesomeric) effects but does not participate in hyperconjugation. Not included.
- Compound 4 (−Cl group): The −Cl group shows −I (inductive) and +M (mesomeric) effects, but no hyperconjugation. Not included.
- Compound 5 (−NO2 group): Similar to Compound 3, exhibits inductive and mesomeric effects but not hyperconjugation. Not included.
- Compound 6 (−CH3 groups attached to a benzene ring): The −CH3 groups exhibit inductive (+I) effects and hyperconjugation due to alpha hydrogens. Mesomeric effect is also observed with the aromatic ring. Included.
- Compound 7 (−COCH3 group): The −COCH3 group exhibits inductive (−I) and mesomeric (−M) effects. However, no hyperconjugation is observed. Not included.
Step 2: Final Count From the analysis, only 4 compounds exhibit all three effects: inductive, mesomeric, and hyperconjugation.
Final Answer: 4.
Top JEE Main Chemistry Questions
What will be the equilibrium constant of the given reaction carried out in a \(5 \,L\) vessel and having equilibrium amounts of \(A_2\) and \(A\) as \(0.5\) mole and \(2 \times 10^{-6}\) mole respectively?
The reaction : \(A_2 \rightleftharpoons 2A\)- At equilibrium the concentrations of and in a sealed vessel at . What will be for the reaction
- Find out the major products from the following reactions
Cobalt chloride when dissolved in water forms pink colored complex $X$ which has octahedral geometry. This solution on treating with cone $HCl$ forms deep blue complex, $\underline{Y}$ which has a $\underline{Z}$ geometry $X, Y$ and $Z$, respectively, are
- The correct order of atomic radii is:
Top JEE Main Resonance Questions
- The difference in energy between the actual structure and the lowest energy resonance structure for the given compound is
Relative stability of the contributing structures is :
- The functional group that shows negative resonance effect is:
- Given below are two statements:
Statement I: On the basis of inductive effect, the order of stability of alkyl carbanions is \(CH_3^->CH_3-CH_2^->(CH_3)_2CH^->(CH_3)_3C^-\).
Statement II: Allyl and benzyl carbanions are more stabilised by inductive effect and not by resonance effect. - Treatment of a gas \(X\) with a freshly prepared ferrous sulphate solution gives a compound \(Y\) as a brown ring. The compounds \(X\) and \(Y\) are :
Top JEE Main Questions
- In a hydrogen like atom, when an electron jumps from the $M$ - shell to the $L$ - shell, the wavelength of emitted radiation is $\lambda$. If an electron jumps from $N$-shell to the $L$-shell, the wavelength of emitted radiation will be :
- Two masses $m$ and $\frac{m}{2}$ are connected at the two ends of a massless rigid rod of length $l$. The rod is suspended by a thin wire of torsional constant $k$ at the centre of mass of the rod-mass system(see figure). Because of torsional constant $k$, the restoring torque is $\tau =k\theta$ for angular displacement $\theta$. If the rod is rota ted by $\theta_0$ and released, the tension in it when it passes through its mean position will be:
What will be the equilibrium constant of the given reaction carried out in a \(5 \,L\) vessel and having equilibrium amounts of \(A_2\) and \(A\) as \(0.5\) mole and \(2 \times 10^{-6}\) mole respectively?
The reaction : \(A_2 \rightleftharpoons 2A\)- The value of is
- The number of terms of an is even. The sum of the odd terms is and of the even terms is . The last term exceeds the first by . Then the number of terms in the series is ______.