In Williumson synthesis, ethoxyethane is prepared by (a) Heating sodium ethoxide with ethyl bromide (b) Passing ethanol over heated alumina (c) Heating ethanol with dry \(\mathrm{Ag}_{2} \mathrm{O}\) (d) Treating ethyl alcohol with excess of at \(430-440 \mathrm{~K}\)

Understanding the preparation of ethoxyethane, commonly known as diethyl ether, is fundamental for students delving into organic chemistry, particularly those preparing for exams like NEET. During the Williamson synthesis, ethoxyethane is produced via a two-step process. The first step involves generating an alkoxide salt, sodium ethoxide in this case, which is then reacted with a primary alkyl halide such as ethyl bromide.

This particular synthesis is widely studied due to its utility in forming ethers, a significant class of organic compounds. By controlling the reactants, different types of ethers can be synthesized, demonstrating the versatility of Williamson synthesis. For the preparation of ethoxyethane, the chemical equation is as follows:\[ \text{CH}_3\text{CH}_2\text{ONa} + \text{CH}_3\text{CH}_2\text{Br} \rightarrow \text{CH}_3\text{CH}_2\text{OCH}_2\text{CH}_3 + \text{NaBr} \]
Students preparing for competitive exams such as NEET must focus on understanding each step of the reaction and the nature of the reactants to master the concept behind ethoxyethane preparation.

The reaction involving an alkoxide salt is crucial in organic synthesis. In the context of Williamson synthesis, the alkoxide salt reacts with a primary alkyl halide to produce ether. The alkoxide salt is typically formed by the reaction of an alcohol with a metallic base, such as sodium.

For example, sodium ethoxide is generated from ethanol and sodium:\[ \text{CH}_3\text{CH}_2\text{OH} + \text{Na} \rightarrow \text{CH}_3\text{CH}_2\text{ONa} + \text{H}_2 \]
Comprehending this reaction requires an understanding that the alkoxide ion (\text{CH}_3\text{CH}_2O}^{-}) is a strong nucleophile, which then attacks the electrophilic carbon atom in the primary alkyl halide, culminating in the formation of the ether product. When diving into the mechanisms of such reactions, students, especially those reviewing for NEET, should pay close attention to the roles of nucleophiles and electrophiles in organic reactions.

Primary alkyl halides are pivotal intermediates used in various organic reactions, including the Williamson synthesis. A primary alkyl halide contains a halogen atom bound to a primary carbon atom, which is a carbon directly attached to only one other carbon atom. These halides are typically more reactive in nucleophilic substitution reactions compared to secondary and tertiary alkyl halides.

During the synthesis of ethoxyethane, ethyl bromide (a primary alkyl halide) is targeted by the nucleophilic alkoxide ion. The primary carbon is less hindered and more accessible to the nucleophile, therefore favoring the S\textsubscript{N}2 mechanism:\[ \text{CH}_3\text{CH}_2\text{ONa} + \text{CH}_3\text{CH}_2\text{Br} \rightarrow \text{CH}_3\text{CH}_2\text{OCH}_2\text{CH}_3 + \text{NaBr} \]
For NEET exam preparation, understanding the reactivity order of alkyl halides and their suitability in different reactions is essential. Emphasis should be placed on recognizing the structure and reactivity of primary alkyl halides to predict the outcome of reactions accurately.

Organic chemistry stands as a significant segment in the NEET (National Eligibility cum Entrance Test) syllabus, which assesses the medical aspirants in India. The questions frequently touch upon reaction mechanisms, preparation of compounds, and functional group transformations.

Williamson synthesis, for instance, is not just about memorizing the process, but also about understanding the underlying concepts of nucleophilic substitution reactions, the nature of reactants, and the interpretation of organic reaction mechanisms. Aspirants should practice by solving multiple problems, focusing on the step-by-step mechanism of reactions and their practical implications in real-world applications.

Additionally, interrelating concepts such as the physical properties of compounds, purification techniques, and spectroscopy can provide a comprehensive understanding of organic chemistry for NEET. Grasping the principles of organic synthesis, like Williamson synthesis, is vital in scoring well and should be studied meticulously with a clear strategy and consistent practice.