The most stable carbocation is:

1. 

2. 

3. 

4. 

The electromeric effect in organic compounds is a

1. temporary effect

2. permanent effect

3. temporary-permanent effect

4. none of the above

The stability of 2,3-dimethyl but-2-ene is more than 2-butene. This can be explained in terms of:

1. Resonance

2. Hyperconjugation

3. Eectromeric effect

4. Inductive effect

(CH₃)₄N⁺ is neither an electrophile, nor a nucleophile because it:

1. Does not have electron pair for donation as well as cannot attract electron pair

2. Neither has electron pair available for donation nor can accommodate electron since all shells of N are fully occupied.

3. Can act as Lewis acid and base

4. None of the above

Which of the following is an electrophilic reagent?

1. RO^-

2. BF₃

3. NH₃

4. RO····H

The-I effect is shown by:

1. -COOH

2. -CH₃

3. -CH₃CH₂

4. -CHR₂

Sulphur trioxide is:

1. an electrophile              2. a nucleophile

3. a homolytic agent          4. a base

Allyl isocyanide has:

1. 9σ and 4p -bonds.

2. 8ơ and 5p -bonds

3. 9ơ, 3p and 2 non-bonded electrons

4.  8ơ, 3p and 4 non-bonded electrons

The least stable resonance structure among the following is:

Hyperconjugation involves overlap of the following orbitals:

(1) σ - σ

(2) σ - p

(3) p - p

(4) π - π