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 \(4\pi\) bonds.

2. 8σ and \(5\pi\) bonds.

3. 9σ, \(3\pi\) and 2 non-bonded electrons.

4. 8σ, \(3\pi\) 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

Buta-1,3-diene and But-2-yne are:

1. position isomers

2. functional isomers

3. chain isomers

4. tautomers

In the following carbocations, the most stabile carbocation:

(1)  RCH₂C+H_{3         (2)} 

_{(3)                  (4)} 

The number of optical isomers of pent-3-en-2-ol is:

1. 2             
2. 4
3. 8             
4. 16

Geometrical isomerism is caused:

1. by restricted rotation around C=C bond

2. by the presence of one asymmetric carbon atom

3. due to the different groups attached to the same functional group

4. by swing of hydrogen atom between two polyvalent atoms.