Organic Chemistry – Some Basic Principles and Techniques

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

Arrange the following in increasing order of stability 1. (CH3)2- C-CH2-CH3 2. (CH3)3- C 3. (CH3)2- CH 4. CH3- CH2 5. CH3

1. 5 < 4 < 3 < 1 < 2
2. 4 < 5 < 3 < 1 < 2
3. 1 < 5 < 4 < 3 < 2
4. 5 < 4 < 3 < 2 < 1

What is the hybridisation state of benzyl carbonium ion? [figure]

1. sp2
2. spd2
3. sp2d
4. sp3

Homolytic fission of the following alkanes forms free radicals CH3-CH3, CH3-CH2-CH3, (CH3)2CH-CH3, CH3-CH2-CH(CH3)2. Increasing order of stability of the radicals is

1. (CH3)2 C-CH2CH3 < CH3- CH-CH3 < CH3- CH2 < (CH3)3 C
2. CH3- CH2 < CH3- CH-CH3 < (CH3)2 C-CH2-CH3 < (CH3)3 C
3. CH3- CH2 < CH3- CH-CH3 < (CH3)3 C < (CH3)2 C-CH2CH3
4. (CH3)3 C < (CH3)2 C-CH2CH3 < CH3- CH-CH3 < CH3- CH2

Which of the following chemical system is non aromatic?

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

Which nomenclature is not according to IUPAC system?

1. Br-CH2-CH=CH2 1-Bromoprop-2-ene
2. [figure] 4-Bromo-2,4-dimethylhexane
3. [figure] 2-Methyl-3-phenylpentane
4. [figure] 5-Oxohexanoic acid