Question

How many compounds among the following compounds show inductive, mesomeric as well as hyperconjugation effects?

Answer 1

Step 1: Analyze each compound - Compound 1 (− OCH 3 group attached): The − OCH 3 group exhibits both inductive (− I) and mesomeric (+M) effects. However, hyperconjugation is not applicable here. Not included.

• Compound 2 (Alkene with − CH 3): The − CH 3 group shows inductive (+I) and hyperconjugation effects due to the presence of alpha hydrogens. Mesomeric effect is not present. Not included.
• Compound 3 (− NO 2 group): The − NO 2 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 (− NO 2 group): Similar to Compound 3, exhibits inductive and mesomeric effects but not hyperconjugation. Not included.
• Compound 6 (− CH 3 groups attached to a benzene ring): The − CH 3 groups exhibit inductive (+I) effects and hyperconjugation due to alpha hydrogens. Mesomeric effect is also observed with the aromatic ring. Included.
• Compound 7 (− COCH 3 group): The − COCH 3 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.