Problem 115 - A Complete Resource Book in Chemistry for JEE Main

Question

Vinyl carbinol is (a) \(\mathrm{HO}-\mathrm{CH}_{2}-\mathrm{CH}=\mathrm{CH}_{2}\) (b) \(\mathrm{CH}_{3}-\mathrm{C}\left(\mathrm{CH}_{2} \mathrm{OH}\right)=\mathrm{CH}_{2}\)(c) \(\mathrm{CH}_{3}-\mathrm{CH}=\mathrm{CH}-\mathrm{OH}\) (d) \(\mathrm{CH}_{3} \mathrm{C}(\mathrm{OH})=\mathrm{CH}_{2}\)

Step-by-Step Solution

Answer

Option (a) is vinyl carbinol: \( \mathrm{HO}-\mathrm{CH}_{2}-\mathrm{CH}=\mathrm{CH}_{2} \).

Step 1: Understanding the Structure of Vinyl Carbinol

Vinyl carbinol is a simple unsaturated alcohol that includes an OH (hydroxyl) group directly attached to one of the carbon atoms in the vinyl group, which is characterized by a carbon-carbon double bond (C=C). This compound is more specifically a primary alcohol, with the hydroxyl group (OH) linked to a primary carbon atom.

Step 2: Identify the Structural Components

Analyze options by identifying both the vinyl group (a section with a C=C bond) and a primary alcohol (OH directly attached to primary carbon). In a molecular structure, prioritize identifying C=C and the attachment of an OH group.

Step 3: Analyze Option (a)

The formula is: \[ \text{HO}-\text{CH}_2-\text{CH}=\text{CH}_2 \] This structure starts with an OH group on a CH2 unit, which is followed by a C=C bond, fitting vinyl carbinol's description.

Step 4: Verify If Option (a) is Correct

Structure (a) meets the conditions of a primary alcohol with an OH group attached to the primary carbon before the vinyl group, accurately representing vinyl carbinol.

Key Concepts

Vinyl Carbinol

Vinyl carbinol is a specific type of organic compound that belongs to the family of alcohols. It features a unique molecular structure with a carbon-carbon double bond, which is commonly referred to as a vinyl group. This vinyl group is directly attached to an OH (hydroxyl) group, marking it as an alcohol.

The presence of the vinyl group means that vinyl carbinol is unsaturated. In chemistry, unsaturated compounds contain at least one carbon-carbon double bond in their structure.

• "Vinyl" indicates the presence of the C=C bond.
• "Carbinol" refers to the alcohol part, with the OH group attached.

This gives vinyl carbinol distinctive properties that can be explored both in academic and practical applications, such as in chemical synthesis and material production.

Unsaturated Alcohol

Unsaturated alcohols, such as vinyl carbinol, are characterized by both an OH group and one or more carbon-carbon double bonds within their structure. This dual characteristic imparts unique chemical properties, making such compounds interesting subjects of study in organic chemistry.

The presence of unsaturation changes how alcohols behave in chemical reactions. Here are some unique points about unsaturated alcohols:

• Reactivity: The double bond can participate in reactions like hydrogenation, where it can be converted into a single bond by the addition of hydrogen gas.
• Physical Properties: The double bond often influences boiling and melting points, as well as solubility in water or organic solvents.

Understanding these properties is crucial for predicting how these compounds will behave under different chemical conditions.

Primary Alcohol

A primary alcohol is identified by the attachment of its hydroxyl group (–OH) to a primary carbon atom. In a primary alcohol, the carbon holding the OH group is connected to only one other carbon atom.

This structural feature influences the chemical behavior of primary alcohols, including vinyl carbinol. Some relevant aspects of primary alcohols are:

• Reactivity: Primary alcohols are generally highly reactive and can undergo oxidation to form aldehydes and further oxidative reactions to form carboxylic acids.
• Utilization: They are often used in the production of esters and ethers, which are valuable in many industrial applications.

In the case of vinyl carbinol, this primary aromatic structure is crucial to its reactivity and the reactions it participates in.

Molecular Structure Analysis

Analyzing the molecular structure of compounds like vinyl carbinol is essential for understanding their chemical properties and uses. Molecular structure analysis involves interpreting the way atoms in a molecule are connected, determining how these connections influence the compound’s behavior.

Key aspects of molecular structure analysis include:

• Identifying Functional Groups: Like the hydroxyl (OH) group in alcohols.
• Understanding Connectivity: How atoms are arranged and bonded; for vinyl carbinol, this includes the recognition of the vinyl group and its attachment to the hydroxyl group.
• Inferring Properties: Based on the structure, predicting physical properties and potential reactions.

Through techniques like spectroscopy and computational chemistry, scientists can predict and confirm molecular structures, set the groundwork for further chemical synthesis or transformation.