Question 1

The IUPAC name of the compound $CH3-CH(CH3)-CH2-CH3$ is:

Accepted Answer

The longest carbon chain contains 4 carbon atoms (butane). Numbering starts from the end nearer to the substituent (methyl group at carbon-2). Therefore, the IUPAC name is 2-methylbutane.

Question 2

The temporary effect in which a dipole is induced in a molecule in the presence of an attacking reagent is called:

Accepted Answer

Electromeric effect ($E$-effect) is a temporary effect defined as the complete transfer of a shared pair of $\pi$-electrons to one of the atoms joined by a multiple bond in the presence of an attacking reagent.

Question 3

Homolytic cleavage of a covalent bond gives:

Accepted Answer

In homolytic cleavage, each of the bonded atoms retains one of the electrons of the shared pair, resulting in the formation of free radicals.

Question 4

The hybridization of carbon atoms in acetylene ($C2H2$) is:

Accepted Answer

In acetylene ($CH\equiv CH$), each carbon atom is attached to one hydrogen atom by a single bond and to another carbon atom by a triple bond, making it sp hybridized with linear geometry.

Question 5

Which of the following carbocations is most stable?

Accepted Answer

Tertiary carbocations are the most stable due to a greater number of hyperconjugative structures and maximum +I effect of alkyl groups dispersing the positive charge.

Organic Chemistry – Some Basic Principles and Techniques