Question

The correct option for the following reaction is (A) 10 monochlorinated product will be obtained (B) 7 fractions will be obtained on fractional distillation (C) 3 enantiomeric pair will be obtained (D) 6 resolvable products will be obtained

Short answer

The correct answer cannot be determined without knowing the exact reactant in the monochlorination reaction. The options provided involve understanding monochlorinated product formation, fractional distillation, and optical isomerism in the context of an alkane reaction with chlorine. However, without specific reactant details, it is inconclusive as it stands and needs more information to determine the correct choice.

Step-by-step solution

Understand the nature of the reaction

From the options given, it can be inferred that the reaction in question is a halogenation reaction, more specifically monochlorination. In this kind of reaction, one hydrogen atom in an alkane is replaced by chlorine, resulting in a monochlorinated product. The total number of distinct monochlorinated products formed is dependent on the number of non-equivalent hydrogen atoms in the starting alkane.

Analyze the possible products of the reaction

The number of different products formed would depend on the alkane used. If the initial molecule has several different types of hydrogen atoms (i.e., on primary, secondary, tertiary carbons), it could result in multiple unique monochlorinated products.

Recognize the concept of optical isomerism

Optical isomers (enantiomers) are chiral molecules that are mirror images of each other and are non-superimposable. Each chiral center in a molecule will produce two enantiomers. The number of molecules with chiral centers will affect the number of obtained enantiomeric pairs

Understanding Fractional Distillation

Fractional distillation is used to separate mixtures into its component parts, or fractions, such as in separating chemical compounds by their boiling point. Each unique compound will form a seperate fraction.

Evaluate each option against the nature of halogenation reactions, the generated products, and principles of optical isomerism and fractional distillation

Simply by the general nature of chlorination reactions, the alkane used, and the concepts of enantiomers and fractional distillation, it will be difficult to determine the correct option without knowing the exact reactant. Since the exact molecule is not mentioned, all the options have a potential to be correct depending on the starting alkane. However, identifying the right option would require detailed information about the structure and type of the starting alkane in the reaction. Therefore, the query is inconclusive as it stands and needs more specific details to determine the correct choice.

Key concepts

Halogenation Reaction

Halogenation reactions are a fundamental part of organic chemistry, particularly relevant to students preparing for JEE Main and Advanced. The concept entails the substitution of a hydrogen atom in an alkane with a halogen atom. Chlorination is a common type of halogenation, where chlorine is the substituent.

During the process, the alkane undergoes a radical substitution reaction, which can lead to several different products. This diversity arises because the halogen can potentially replace a hydrogen atom on any carbon in the molecule, forming isomers. The number of distinct monochlorinated products correlates with the number of unique types of hydrogen atoms present. For instance, hydrogen atoms on a primary carbon result in different products than those on secondary or tertiary carbons.

It's worth noting that while halogenation increases the number of possible compounds, it can also introduce chirality if a chiral center is formed and this lies at the intersection with optical isomerism.

Optical Isomerism

Understanding optical isomerism is crucial in the field of stereochemistry, and forms a significant part of the JEE syllabus. Optical isomerism arises when compounds possess chirality, meaning that they contain an asymmetric carbon atom—also known as a chiral center—and have non-superimposable mirror images. These mirror-image molecules are called enantiomers.

For a molecule to exhibit optical isomerism, it needs to lack a plane of symmetry. Students need to visualize molecular structures and identify chiral centers to predict the presence of optical isomers. Each chiral center in a molecule typically gives rise to two enantiomers; hence, the number of possible enantiomers can usually be calculated as \(2^n\), where \(n\) is the number of chiral centers.

This concept particularly intersects with halogenation reactions when a chirality-inducing halogen is introduced, potentially doubling the number of distinct products due to the creation of enantiomeric pairs. For instance, replacing a hydrogen atom with a halogen might convert a non-chiral molecule into one with a chiral center.

Fractional Distillation

Fractional distillation is a pivotal separation technique in organic chemistry and is particularly emphasized in JEE Main and Advanced preparations. It's used to separate complex mixtures into individual components based on differences in boiling points.

The process involves the heating of a liquid mixture to vaporize it partially. The vapor then ascends through a column, where it undergoes repeated condensation and vaporization cycles. Components with lower boiling points will reach the top of the column faster and are collected first, followed by higher boiling point components.

This technique is instrumental when dealing with products of halogenation reactions. It can be used to separate monochlorinated products valid provided they have sufficiently different boiling points, allowing for the purification of individual isomers. Moreover, fractional distillation is not suitable for separating enantiomers, as optical isomers typically have identical physical properties like boiling points. Therefore, while fractional distillation efficiently separates structural isomers, it cannot resolve optical isomers, which requires different techniques like chromatography or crystallization.