Organic Chemistry – Some Basic Principles and Techniques · Question 29

Which of the following is the most correct electron displacement for a nucleophilic reaction to take place?

1. [figure]
2. [figure]
3. [figure]
4. [figure]

Consider the following compounds : [figure] Hyperconjugation occurs in

1. III only
2. I and III
3. I only
4. II only

The enolic form of ethyl acetoacetate as shown below has [figure]

1. 9 sigma bonds and 2 pi-bonds
2. 9 sigma bonds and 1 pi-bond
3. 18 sigma bonds and 2 pi-bonds
4. 16 sigma bonds and 1 pi-bond.

In which of the following compounds, the C–Cl bond ionisation shall give most stable carbonium ion?

1. [figure]
2. [figure]
3. [figure]
4. [figure]

Given : [figure] The enthalpy of hydrogenation of these compounds will be in the order as

1. II > III > I
2. II > I > III
3. I > II > III
4. III > II > I

Which of the following organic compounds has same hybridization as its combustion product (CO2)?

1. Ethane
2. Ethyne
3. Ethene
4. Ethanol

The radical, [figure] is aromatic because it has

1. 7 p-orbitals and 7 unpaired electrons
2. 6 p-orbitals and 7 unpaired electrons
3. 6 p-orbitals and 6 unpaired electrons
4. 7 p-orbitals and 6 unpaired electrons.

The structure of isobutyl group in an organic compound is

1. [figure]
2. [figure]
3. [figure]
4. [figure]

Structure of the compound whose IUPAC name is 3-Ethyl-2-hydroxy-4-methylhex-3-en-5-ynoic acid is

1. [figure]
2. [figure]
3. [figure]
4. [figure]

The outer orbitals of C in ethene molecule can be considered to be hybridized to give three equivalent sp2 orbitals. The total number of sigma (σ) and pi (π) bonds in ethene molecule is

1. 3 sigma (σ) and 2 pi (π) bonds
2. 4 sigma (σ) and 1 pi (π) bonds
3. 5 sigma (σ) and 1 pi (π) bonds
4. 1 sigma (σ) and 2 pi (π) bonds