Question

Statement (A): Resonating structure with more $\sigma$-bonds charges far apart are more stable.
Statement (B): Unsaturated hydrocarbon shows +I or –I depending upon the group they are attached with.
Statement (C): Carbanion with more % s character are more stable.
Statement (D): In nucleophilic addition to carbonyl group –E (electron-withdrawing) effect is responsible while in electrophilic additions +E is responsible.
Statement (E): Alkene having more alkyl groups have more heat of hydrogenation.
How many statements are correct?

• A. A, B, D, E
• B. B, C, D, E
• C. B, C, D
• D. A, B, C, D, E

Hint:

Greater alkyl substitution increases alkene stability and decreases heat of hydrogenation.

Answer 1

The Correct Option is C

Statement (A):
Resonating structures with minimum charge separation and maximum covalent character are more stable.
Hence, this statement is incorrect.
Statement (B):
Unsaturated hydrocarbons can show +I or –I effect depending upon the nature of substituent attached.
Thus, this statement is correct.
Statement (C):
Carbanions with greater % s-character hold negative charge closer to nucleus, making them more stable.
Thus, this statement is correct.
Statement (D):
In nucleophilic addition to carbonyl compounds, –E (electron-withdrawing) effect increases electrophilicity of carbonyl carbon.
In electrophilic addition to alkenes, +E (electron-donating) effect stabilises carbocation.
Thus, this statement is correct.
Statement (E):
More substituted alkenes are more stable and hence have lower heat of hydrogenation.
Thus, this statement is incorrect.
Step 2: Count correct statements.
Correct statements are B, C and D.
Total = 3