Which of the following is an electrophilic reagent?

1. RO^-

2. BF₃

3. NH₃

4. ROH

The-I effect is shown by:

1. -COOH

2. -CH₃

3. -CH₃CH₂

4. -CHR₂

Which of the following is singlet carbene?

1. (CH₃)₃C⁺

2. C₂H₅-CH

3. ${\mathrm{CH}}_3{\mathrm{CH}}_2{\mathrm{CH}}_2^{-}$

4. CH₂ =CH-${\mathrm{CH}}_2^{+}$

Sulphur trioxide act as:

1. An electrophile             

2. A nucleophile

3. A homolytic agent         

4. A base

Allyl isocyanide has:

1. 9 σ, and 4π-bonds.

2. 8 σ, and 5π-bonds

3. 9 σ, and 3π-bonds, 

4. 8 σ, and 3 π bonds

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

1. Position isomers

2. Functional isomers

3. Chain isomers

4. Tautomers

Diastereomers can be separated by:

1. Fractional distillation

2. simple distillation

3. electrophoresis

4. all of these

In the following carbocations, the most stabile carbocation:

(1)  RCH₂C+H₃         

₍₂₎ 

₍₃₎                

 ₍₄₎ 

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

1. 2             

2. 4

3. 8             

4. 16

The number of geometrical isomers in case of a compound with the structure,

CH₃-CH=CH-CH=CH-C₂H₅ are:

1. Four                 

2. Three

3. Two                 

4. Five