The electromeric effect in organic compounds is a

1. Temporary effect

2. Permanent effect

3. Electromeric effect is only observed in inorganic molecules

4. None of the above

H₂C = O behaves as:

1. Nucleophile

2. Electrophile

3. Both (1) and (2)

4. None of the above 

Which of the following is strongest nucleophile?

1. Br^-

2. $\stackrel{..}{\mathrm{O}}H$

3. $\stackrel{..}{\mathrm{C}}N$

4. ${\mathrm{C}}_2{\mathrm{H}}_5\stackrel{..}{\mathrm{O}}$

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. electromeric 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. 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